Fast and fresh foods; Fast and Fresh, by Julie Dannenbaum. New York: Harper & Row. $13.95.

Flexibility and a sense of humor go into the collection of recipes in Julie Dannenbaum's new cookbook. They are practical and suitable to the transient fast life most families lead today.

The approach is one of simplicity, but there are elegant menus, creative ideas, and ways of presenting foods to make them appealing.

"Fast and Fresh" is an outstanding list of really interesting, easy, quick-to-prepare menus. It is thoroughly professional, but brief.

Once you are accustomed to fine cooking, it is difficult to go back to ordinary meals or frozen dinners, often the only obvious alternative when time becomes limited after a busy workday.

Good food properly served and enjoyed does not necessarily mean leisurely dining, but should be a time for people to talk and share their lives day to day , the author believes. Then she gets down to basics -- in which all menus are timed for less than 60 minutes.

No meal requires more than one sauce, although some of the menus call for made- ahead sauces and stocks. These are in a chapter on "Weekends and Cooking Days." They are very basic menus and should be in everyone's repertoire, like homemade mashed potatoes, the author says.

Julie Dannenbaum, head of a well-known cooking school, Creative Cooking of Philadelphia, also directs cooking schools in Venice, Italy, and the Greenbriar Hotel in West Virginia.

One menu is called "Stay-For-Dinner Menu for 3" includes Julie's 15-Minute Chicken, Puffed Potato Wedges, Shredded Carrots with Oil and Vinegar, and Sabayon over Sliced Bananas.

A Vegetarian Dinner includes Celery with Coarse Salt, Eggplant Bake, Wheat Germ Muffins, and Oranges with Fresh Coconut. A spring menu lists Lamb Patties with Rosemary, Baked Potato Slices, and Rhubarb Crisp.

Desserts include lots of fresh fruit or easily made fruit dishes. "A Trendy Hamburger Dinner" has Hamburgers with Roquefort Cream, Parsnip Puree, Crisp Watercress, and grapefruit and strawberries for dessert.

"Leftovers for a Picnic" includes menus put together from recipes elsewhere in the book. One menu includes Cold Fried Chicken, Red-Skin Potato Salad, Crudites, and Apple Cake or Molasses Cake.

Party ideas include one called cassecroute, from the French casser croute,m meaning "to break a crust." Her interpretation is to serve a hearty dish with a good crusty bread at parties after a game, or on a winter night.

There are a few recipes and menus for the occasion when a person is "long on time and lavish with good intentions" but for the most part the ideas and menus make you realize it is possible to plan menus for the week that can be both fresh and quick to put together after a hard day at the office.

The following recipes from "Fast and Fresh" should provide some good ideas for using fresh summer fruits. Fresh Peach Cobbler 3 cups fresh peaches, peeled and sliced 1/2 cup sugar 8 tablespoons butter 1 cup flour 2 teaspoons baking powder 1 tablespoon sugar 1 teaspoon salt 1/2 cup heavy cream, or less

Lay fruit in 1 1/2-quart baking dish. Sprinkle over 1/2-cup sugar; dot with 4 tablespoons butter.

Make a crust of remaining ingredients. Mix together flour, baking powder, 1 tablespoon sugar, and salt.Cut in 4 remaining tablespoons butter; then add enough heavy cream to make a manageable dough. Mix with a light touch.

Roll out dough on a lightly floured board and place over fruit. Bake at 375 degrees F. for 35 to 40 minutes. Serves 6. Melon Fingers With Lime 1 large honeydew melon 1/2 cup fresh lime juice Grated rind of 2 limes, no pith or white part

Peel honeydew. Remove seeds and fibers. Cut into finger-size pieces. Place in a serving bowl and sprin kle lime juice and grated rind on top. Serves 6.