The Best-laid nutritional plans may go awry at mealtime.Integrating nutrition knowledge with meal preparation is, apparently, a little harderthan it looks. So say many cooks, in a recent Woman's Day magazine studyconducted jointly with the Food Marketing Institute.

In that survey, women said they were more concerned about the cost of food, preparation time and pleasing the family than they were about good nutrition.

Whether the problem is not having time to cook or not wanting to spend much time cooking, quiche solves it. In addition it is inexpensive and, particularly when given a Mexican twist, a good bet for pleasing the family.

Serve the quiche with colorful crookneck squash which have been stir-fried in butter or vegetable oil and seasoned with salt, pepper and oregano.

If your express lane allows for more items, think about picking up a bunch of scallions and ground cumin to add to the quiche. Trim the scallions of their roots, then slice (including any green part that doesn't seem wilted) and sprinkle them over the cheese mixture. Add a scant 1/4 teaspoon of cumin to the milk-egg mixture.

Or you may want to add a salad to the meal. Pick up some pretty, soft leaf lettuce and an avocado and dress it with a simple vinaigrette for a continuation of the Mexican theme.

As usual, it is assumed that the most ill-equipped kitchen has flour, sugar, salt, pepper and some type of butter or vegetable oil.

Homemade pie crust can be made with these ingredients. As with many "from scratch" foods, homemade crust is much tastier than store-bought. It is, admittedly, more trouble. The amount and type of shortening is a matter of preference. Some cooks prefer the flavor of butter even though the resulting pastry is a little more crumbly. Some prefer the picture-perfect crust from the blander shortening. Some prefer the compromise of mixing the two types or of using margarine. A suggested recipe for pie crust follows; a store-bought crust is, therefore, not included in the shopping list.

EXPRESS LANE LIST: mushrooms, monterey jack cheese, eggs, evaporated milk, canned green chilies, pimientos, yellow squash, oregano.

QUICHE MONTEREY (4 to 6 servings) 1 unbaked, deep, 9-inch pie shell 1/4 pound fresh mushrooms 2 tablespoons butter or vegetable oil 4 ounces monterey jack cheese, grated 1/4 cup chopped green chilies 2-ounce jar chopped pimientos, drained 4 eggs 1 1/4 cups evaporated milk

Bake the pastry shell at 375 degrees for about 10 minutes, or until it begins to shrink from the sides of the pan. Slice the mushrooms and saute' them in butter or vegetable oil over medium heat for 5 minutes, or until the moisture has evaporated. Spoon mushrooms into partially baked pie shell. Cover with grated cheese, drained chopped chilies and pimiento. Beat milk with eggs. Pour into pie shell. Bake at 375 degrees for 30 to 35 minutes or until brown and puffed.

PIE CRUST (Makes 1 deep-dish crust) 1 cup all-purpose flour 1/2 teaspoon salt 1/3 cup shortening, margarine or butter 2 tablespoons ice cold water, or as needed

Sift flour and salt together into a small bowl. Add half the shortening and cut in until the mixture resembles cornmeal. Cut in the remaining shortening until it resembles small peas. Sprinkle the dough with 2 tablespoons of water and toss it lightly with a fork. The ingredients should just hold together. As soon as you can gather the dough in a ball, stop handling it. Roll on a floured surface and place in a deep-dish pie pan.