CHRISTMAS ISN'T OVER until the three kings get here, and they're due in this weekend. European families celebrate their arrival with a traditional party that's easily transportable to American soil. The Feast of the Epiphany, January 6, actually falls on Monday this year, but it's generally celebrated on a weekend afternoon or evening.

"We invite children -- it's a children's party," says Francoise Remington, a French woman who now lives in Arlington and celebrates the traditional French f.ete des rois -- or feast of the kings -- with her American husband, her children and friends.

The essential ingredients are a special cake called a galette des rois and paper crowns. Hidden inside the cake is a bean, a button or a tiny porcelain figure. Whoever finds the bean, button or figure in his or her piece of cake reigns over the party as king or queen.

Whether they use a bean or not, the French usually refer to the hidden object as la feve, explains Remington, "because in some parts of France they use a fava bean. When the cake is cut, you can sometimes see where it is, so in my family we would always put the youngest child under the table where she could not see. As each piece was cut, we asked, 'Who is this one for?' " And the child, without seeing, would make the decision.

"The one who gets la feve is the king or queen and gets to choose a counterpart," says Remington. "In my family we were four girls. My father was the only man, so we all knew who was going to be king . . . I know one family with six boys. They always put in six buttons so there will be no fights."

The French custom goes back to the early days of Christianity but has some pagan antecedents. In the Roman feast of Saturnalia, the slave who found a bean hidden in his cake would reign over seven days of carnival -- and have his head chopped off at the end of the week.

In early Christian times, January 6 was celebrated as both the birth and the baptism of Christ. In the fourth century, when Christmas came to be celebrated on December 25, January 6 was observed as the day the wise men arrived in Bethlehem, twelve days after the birth of Christ.

In the Middle Ages, one piece of every cake would be reserved for the poor. Beggars disguised as kings would knock on doors to collect their share. In England, the feast is known as Twelfth Night, and is traditionally the end of the revelry of the Christmas season.

You may find the f.ete des rois a good way to end the holiday season -- one last party before you take down the Christmas tree and send the kids back to school. The cake used varies from country to country, and each province of France has its own version.

The recipe given here is for the Parisian version of a galette des rois, a recipe brought to France from Italy by Catherine de Medici during the Renaissance. While you make the cake, let the children make two simple paper crowns.

FRANCOISE REMINGTON'S GALETTE PARISIENNE A LA FRANGIPANE

Use two circles of puff pastry dough, about eight or nine inches in diameter. Buy frozen puff pastry or filo dough or make it according to instructions in any good cookbook, such as Julia Child's "Mastering the Art of French Cooking, Volume II." Place the bottom puff pastry circle on an ungreased baking sheet.

Next, make creme frangipane, or almond cream filling. Beat together 1 beaten egg, 4 ounces of sugar, 4 ounces of pulverized almonds, 2 tablespoons of melted butter and 1 tablespoon of rum. Spoon the filling onto the circle, leaving about an inch from the edge.

Place the button or bean or porcelain figure in the filling. Cover with the second circle, pinching the sides together.

Paint the top of the cake withbeaten egg yolk and decorate with cut-outs from the leftover pastry dough.

Bake in a 400-degree oven for about 15 minutes. Serves eight.

Three kings cakes -- complete with crowns -- are also available from the Bakery Potomac Metro on Capitol Hill (543-2960) and from the French Market in Georgetown (338-4828).