It took Sharon Claessens about 30 years to find out that food and cooking comforted her. Naturally, she made it a career.

That is, she made natural foods her career. Once she moved to Allentown, Pa., with her Dutch husband after six months of living in Belgium. That was after three months of traveling with 27 others from London to Katmandu.

She went to work in 1979 for Rodale Press, which has just released her latest effort, "The 20-Minute Natural Foods Cookbook."

The natural foods enthusiast should be forewarned that she does not discuss natural foods the way most people do. When Claessens talks about natural foods, she means foods that are relatively unprocessed; she doesn't talk about foods with lots of carob and honey, or other foods that have come to connote "natural."

She cooks the way average people cook. She gained 25 pounds in college and turned to "natural" foods to help her lose weight. Now she cooks with whole wheat, but with butter, too. She uses tofu and tahini, but cream sneaks into her recipes.

When her editor presented her with the idea of a quick natural foods cookbook, she said it was "a terrible idea." People rush too much these days, she said, and one of life's pleasures is to take time to cook. But she soon changed her mind. "I can afford to stand over food and take time with it," she said in a recent interview; "I get paid to do that."

So she devised about 500 recipes, all of which were tested, most of which take 20 minutes (more or less) and about 300 of which made it into the book. Although there is cream and butter in the recipes, Claessens said she tries to make a little flavor go a long way. For instance, the cream of spinach soup has a half-cup cream and 1 cup buttermilk.

Claessens said she cooks a lot of pasta; not only because she loves it, but because it's quick. Her favorite dish, included in the cookbook, is pasta with feta cheese. This dish would go well with a salad, which you might want to start first, since the spaghetti takes so little time.

If your supermarket allows more than eight items in the express lane, check out with basil and dijon mustard -- basil to sprinkle in the spaghetti (about 1/2 teaspoon) and dijon mustard for the salad vinaigrette (about 1 teaspoon).

It's assumed that even cooks in a hurry have a kitchen stocked with flour, sugar, pepper, salt and butter or oil of some kind.

EXPRESS LANE LIST: Whole wheat spaghetti, eggs, feta cheese, peas, romaine lettuce, red wine vinegar, garlic.

SPAGHETTI FETA-S%YLE (2 servings) 1/3 pound thin whole wheat spaghetti 1 cup peas 1 egg 1 cup crumbled feta cheese

Bring a large kettle of water to boil over high heat. Add spaghetti and return water to boil. Reduce heat and boil spaghetti about 10 minutes, or until done to preference. Add fresh peas to water with spaghetti. If using frozen peas, add to spaghetti water, cooking according to package directions. If using canned peas, drain and toss with spaghetti after it is cooked. While the spaghetti cooks, beat egg in a bowl until light and fluffy. Add finely crumbled feta cheese to egg. Drain spaghetti (and peas) and immediately toss with egg and cheese while spaghetti is still hot. Toss until the spaghetti is well coated and serve immediately.

The recipe notes that the success of this dish depends on the flavor of the cheese, so buy one of good quality.

VINAIGRETTE 1 part red wine vinegar 3 parts salad oil or olive oil 1 clove garlic, smashed or minced

Combine red wine vinegar with salad oil or olive oil and garlic. Set aside while you prepare dinner. For salad, toss washed, dried and torn romaine lettuce leaves with vinaigrette.