WHEN Phil Esocoff decided to ask fellow architect Amy Weinstein to marry him, he bought a bag of fortune cookies, extracted the fortune from one with tweezers and inserted his own. Then, he went to a Chinese restaurant, brought along two of the cookies and made arrangements to have them served after dinner, in his-and-hers envelopes. At the restaurant that evening, Weinstein noted the envelopes suspiciously, Esocoff recalls, "and I was probably grinning like a fool." But she opened hers anyway and with that, a partnership was born. Her fortune read: "He's going to pop the question."

Food and architecture are their passions; the similarities, they are quick to point out, are many. "Architects and their spouses tend to be terrific cooks," Weinstein says, "and tend to have a developed appreciation for good food."

Esocoff: "I think architects are more sensitive to the sensuous aspects of life. In other words, the stimulation that you get from beautiful lighting in a room, instead of glaring light bulbs. Or beautiful, finished wood floors. And the same thing is true with food, you just don't slap it on the plate.That's why we're attracted to tarts, also: They're visually beautiful; they're not just a cake with chocolate icing on it."

So several times a year, at least once each season and more frequently during the summer, Esocoff and Weinstein bake tarts. And they go about it with the intensity of architects working on a dream project. To watch them in the kitchen is like watching architects on charrette -- that profession's term for working on deadline at a high creative pitch.

"It's an opportunity to take what we like about our work and do what's fun," Weinstein says.

You might attribute the specialization to their polished sense of color and pattern. Or perhaps because they're used to dealing with complicated projects involving patience and mechanical skill, they're not intimidated by the steps tart banking requires.Regardless of the reason, their tarts not only taste good, they are triumphs of design -- an edible version of what might be regarded as two architects' inclination to reshape the world. The effort has evolved into a tradition, and a study in cooperation and creativity.

They say they've never had any structural failures.

"Phil uses a very high factor of safety," Weinstein says of her husband's slightly-thicker-than necessary pastry. "When an engineer designs a structure he usually throws in a factor of safety of two or something, so should anything horrible happen, like a meteor hitting the building, it will still stand. Phil always designs a high factor of safety in his crust. I like a thin crust, so it's a point of contention between us."

"Well," retorts Esocoff, "it takes a flaky guy to make a tender crust."

On a recent Sunday, Esocoff and Weinstein prepared tarts in their Connecticut Avenue condominium. They were eager to bake; the kitchen was spotless, and the counters were crowded with pretty fruit: pineapple, kiwi, early strawberries, blueberries and green and red grapes.

Six hours later, Esocoff had become sick (a virus, not the food); Weinstein was fading fast, and the kitchen had lost its shine. But the tarts -- one, named Dupont Circle, based on a Le Corbusier radial design, the other using a half-drop pattern and named after Flemish-Bond brickwork -- were beautiful.

The key to an effective fruit design is high contrast in color. Esocoff says he loves vivid colors and uses them whenever possible in his buildings. (For example, the Perpetual American Bank at 915 Rhode Island Ave. NE, which he designed for the firm Keyes Condon Florance, is electric blue and known among colleagues as "The Blue Minnow.") For the Dupont Circle tart, he used green grapes, blueberries and strawberries in a simple wheel pattern -- the basis of Le Corbusier's Radial City. Esocoff also suggests using raspberries (expensive, but lush in color), cranberries or concord grapes, against a background of kiwi, pineapple or peach.

Weinstein tends to focus more on intricate pattern. (She has lectured on pattern at the University of Maryland, where she teaches part-time in addition to managing her own practice.) For the Flemish-Bond tart, she used green grapes with blueberries, in a radial half-drop pattern. Typically, this pattern is used horizontally -- in brickwork, for example, or, as Weinstein points out, on traditional cookbook covers.

Combining their interests, Weinstein and Esocoff work together effeciently, making at least two tarts per session. Both shop for and clean the fruit, but baking chores are divided in advance. Using combinations and variations on basic Julia Child and Craig Claiborne recipes, Weinstein blends the filling while Esocoff prepares the crust.

The designs are always different and develop fairly spontaneously, although before actually committing fruit to filling, they practice in empty tins. They say most kitchen conversation is about the decoration, often trying to remember what they did before. And they rarely work on the same tart. They don't have a contest exactly, but they do "crit" each other's work, as in architectural critiques. Of course, there are plenty of design books nearby for easy reference. Results are "like fireworks," as Esocoff modestly puts it, and always shared with friends or family for a special occasion.

Tart baking began "about five years ago," Esocoff explains, and wasn't an immediate success. "When we were living in Philadelphia, we got invited to this picnic. It was run by these people who used to work at the AIA [American Institute of Architecture]. They invited all their friends who like to cook, and you either had to bring a fancy dessert or a fancy salad. And they had judges.

"So so we brought this tart, and it had a sweet cream and cream cheese kind of custard underneath the fruit, and it needed refrigeration. It turned out to be a 95-degree day. It looked okay; it looked beautiful. And they also had people who were very prejudiced toward chocolate on the judging -- and they picked a real delicious dessert that won..."

"A mocha cake," interrupts Weinstein.

"Yeah," says Esocoff, pausing as if to savor the memory. "And they made a comment after the contest that they were moved by our dessert to institute a new category, for the best visuals. So the next year we came back, and we had a more stable thing that held up better in warm weather..."

Weinstein: "Very traditional. A ring of strawberries."

"Yeah," Esocoff says. "Rings of strawberries and maybe some blueberries. And not only did we win the best visuals, we also won the best-tasting. We had gotten the custard to be stable for outdoor eating. So we retired then, undefeated."

"We retired by moving to Washington," Weinstein says, adding, "The truth is the very first year we went to that picnic we brought store-bought cupcakes."

"That's true," says Esocoff, blushing. "And we were embarrassed and ashamed."

Weinstein: "So the next year we made a tart." TART PASTRY (Enough for a 12-inch tart) 1 3/4 cups all-purpose flour Pinch of salt 2 to 2 1/2 tablespoons sugar 9 tablespoons butter, chilled 2 1/2 tablespoons shortening 1/2 cup ice water, with 1 egg yolk beaten in 2 ounces Baker's German chocolate (to spread over Dupont Circle pastry) or six egg whites, unbeaten (to spread over Flemish-Bond pastry; reserve the whites from the yolks need for cream filling)

In the bowl of a food processor fitted with a steel blade, and flour and salt. Add butter and shortening in small bits. Turn on processor for about three seconds. Add everything except two tablespoons of ice water/egg yolk mixture. Again, turn on for three seconds. Pastry is ready when it begins to mass on the blade. When you lift dough out of processor, lightly massage it on counter and pat into a cake, to press out any remaining air. Form into ball, dust with flour and wrap in plastic. Set in refrigerator for two hours until well chilled.

If you want to make both tarts, do not double the recipe because it won't fit in the processor. Instead, process two dough recipes separately, and refrigerate the dough in two balls.

Grease a 12-inch tart tin with butter. Esocoff uses a Teflon rolling skin, taped to the counter (avoid warm surfaces), to roll out the dough. This helps him to roll out just the right amount -- circular measurements are drawn on the skin -- and then gives him support to plop the dough into the tin. It also helps to beat the dough with a rolling pin before rolling it out. After dough is in tins, prick pastry with a fork every quarter-inch. Refrigerate again for 30 minutes. Butter a sheet of aluminum foil and press down over the pricked pastry. Weigh the foil down by filling it with rice to keep the dough flat throughout baking. Bake both tins for about eight minutes in a 350-degree oven. Remove the foil and rice, prick again ("Be careful of the hot rice," warns Esocoff), put foil and rice back on, and bake again for a few minutes.

When making tarts, a layer of either egg white or chocolate is necessary to seal the pastry and protect it from the fruit juices and moist filling. For the Dupont Circle tart, Esocoff used chocolate beneath the cream-custard. On the Flemish-Bond, Weinstein used egg white.

If making Dupont Circle tart, melt the chocolate, thinning with a dash of liqueur if desired. Remove shell from oven, remove foil and rice and return to oven a third time to allow dough to brown. Do this before brushing on the chocolate. Wait until shell has cooled before adding chocolate layer, then set aside to let the chocolate harden. Do not bake after chocolate layer has been added.

If making Flemish-Bond tart, remove shell from oven, remove foil and rice and brush pastry shell with unbeaten egg whites. Bake again for a third time (about three minutes) to brown. Allow to cool before adding filling. LEMON-LIME FILLING FOR FLEMISH-BOND (Enough for a 12-inch tart) 1 medium apple 3 large eggs 2/3 cups sugar Grated rind of two limes 1/3 cup fresh lemon juice, strained

You must blend this filling immediately before baking it, or it will separate and be ruined. Peel, core and grate the apple, then spread evenly over the pastry. Beat eggs, sugar, lime rind and lemon juice together until thick and creamy. Fill shell but leave a narrow margin around edge of tin to allow mixture to spread. Bake at 350 degrees for about 30 minutes, until filling has puffed slightly and has just begun to turn golden brown on top. Cool at least 15 minutes in refrigerator before decorating. CREAM CUSTARD FILLING FOR DUPONT CIRCLE TART (Enough for a 12-inch tart) 2 cups milk 6 egg yolks, beaten 1/2 cup sugar 1/2 cup all-purpose flour 3 tablespoons butter 1 tablespoon kirsch Pinch salt

Heat the milk over medium heat.Beat the egg yolks in a medium-size non-aluminum saucepan and gradually add the sugar. Continue beating until thick and pale yellow. Then beat in flour until well mixed. Dribble in the hot milk, using only two-thirds or three-fourths of it, until pudding texture is achieved. Leftover milk may be used to thin, if necessary. Move saucepan to the stove, beat over moderately high heat until smooth, then lower heat and stir with a wooden spoon. Remove from heat and beat in butter a little at a time. Beat in kirsch and salt. Do not bake. Cool in refrigerator about 30 minutes, in saucepan.If too stiff, add remaining hot milk to thin and return to refrigerator to chill. Pour into tart shell. FRUIT DECORATION (Enough for a 12-inch tart) 1 1/2 pints strawberries (for Dupont Circle) 1 pint blueberries 1/4 pound green grapes 1/4 pound red grapes (for Flemish Bond) 1 kiwi (for Flemish Bond) 1 cup red currant jelly 1 cup apple or apricot jelly Dash of kirsch

The trick is to find pretty fruit in contrasting colors and even sizes. Wash, pare and dry fruit before decorating. Filling should be cool and firmly set. Weinstein and Esocoff practice in an empty tin or on the counter before applying the fruit.

To decorate Flemish-Bond tart: Place a kiwi slice in center to use as a point of reference. Then lay the outside ring of whole red grapes. Next, lay a ring of green grapes cut in half (flat side down). Divide blueberries into large, medium and small sizes. Lay a large blueberry below a green grape. Then, lay a green grape half next to the blueberry. Then, another large blueberry. Alternate large blueberries and green grape halves around the circle. Continue this pattern for three rows, using smaller blueberries as you go farther into the circle. Then lay a ring of solid red grapes cut in half. Fill in remaining space between red grapes and kiwi with blueberries.

To decorate Dupont Circle tart: Place a large whole strawberry in center of tart to use as a point of reference. Then lay the outside ring of whole strawberries, choosing the biggest and prettiest. Next, a ring of solid large blueberries. Lay down three "avenues" of blueberries, three rows wide, intersecting the strawberry. Fill in remaining space with green grapes, cut in half, flat side down. If you don't have a large enough strawberry for the center, use three as shown in picture.

After pattern is set, heat the jellies (in separate saucepans) until liquid. Add kirsch for flavoring and to thin. Brush red currant jelly on the dark fruit, such as red grapes, strawberries, blueberries. Brush the apple or apricot jelly on the light fruit, such as green grapes. This will glaze the fruit and make it sparkle. To store without harming decoration, use an air-tight container, and keep in a cool place. Refrigerate if keeping overnight, but the tarts are best eaten same day.