SPINACH IS as American as Popeye, though perhaps not so well loved by children. In fact, it seems to be the major vegetable struggle with children - at least until they get a little older and begin to recognize it for its value and taste.

The two type of spinach we know are the smooth leaf, which is generally canned or frozen, and the curly leaf, which is most commonly sold fresh in produce sections. New Zealand spinach is not spinach, strictly speaking, but it is a good imposter. It grows prolifically, even wildly, and is very high in nutritional value. Its young leaves are very good in salads.

All spinach is a good source of vitamins A and C, iron and folic acid. It also contains calcium and a substance called oxalic acid. During the digestive process, the oxalic acid combines with the calcium and the combination is not digestible. Therefore, the calcium, for the most part, is rendered useless to the body. If you include other calcium rich foods with your spinach consumption, this will not be a problem.

Always wash spinach well, as it tends to be gritty. It's best to cook it in a steamer so that the greens are above water. Spinach contains so much water itself that it shrinks drastically in cooking. I much prefer eating spinach in salads, and here are three of my favorites:

EASTERN SPINACH SALAD

(4 or 5 servings) 2 tablespoon sesame seed 1/2 cup peanut oil 1/4 cup soy sauce 2 tablespoons lemon juice 2 tablespoons grated onion 1/2 teaspoon honey 1 pound spinach, well washed and steamed 1 cup bean sprouts 1 can (2 ounces) water chestnuts

Toast sesame seeds in oven at 350 degrees until golden. In blender mix oil, soy sauce, lemon juice, onion and honey. Toss with well-drained spinach, bean sprouts, water chestnuts, and sesame seeds.

SPINACH SUPPER SALAD

(4 or 5 servings) 1 pound spinach, well washed, stemmed and drained 5 slices bacon 2/3 cup olive oil 1/2 cup garlic wine vinegar 1 teaspoon honey 1 teaspoon dry mustard 1/2 teaspoon curry powder 1 cup chopped green onions 1 cup chopped celery 3 hardboiled eggs, grated 1/3 pound cooked shrimp Salt and pepper

Chop spinach finely and refrigerate. Fry bacon until crisp, crumble and set aside. In blender, put oil, vinegar, honey, mustard and curry powder. Blend well and toss with bacon, spinach, onions, celery, eggs and shrimp. (This is quite a bit of dressing - add enough only to your taste).

SPINACH NUT SALAD WITH YOGURT DRESSING

(4 servings) 1 pound spinach 1/2 Bermuda onion, thinly sliced 1 cup coarsely chopped walnuts 2/3 cup plain yogurt 1/3 cup mayonnaise 3 tablespoons chopped ripe olives Salt and pepper

Wash spinach well and drain. Chop finely, toss with onions and nuts and set aside. Mix together yogurt and mayonnaise and stir in chopped olives. Toss salad with dressing just before serving.