Q. Cauliflower heads are sometimes one-third leaves and stems. Can these be cooked? Are they nutritious? If so, how would you prepare them?

A: The stems and leaves of cauliflower are edible and nutritious, though also fibrous and pungent. Being green and fresh, they would probably be reasonable sources of vitamin A and C. This is true of the green leaves of just about any plant (one should not, however, cook and eat the leaves of just any plant -- many are poisonous). The leaves contain a number of pigments, which their cells use to trap light and convert it to a usable form of energy.

To cook, remove the leaves from the stems and plunge the stems into boiling, lightly salted water (1 1/2 teaspoons salt per quart of water). Cook until almost soft. Add the leaves and cook them with the stems until soft. Drain and cool.

Slice leaves and stems into small pieces with a knife. With your fist or with the flat side of a large knife or cleaver, smash several garlic cloves and peel off their skins. Heat a little olive or peanut oil or bacon fat in a skillet until hot and add the garlic cloves. Saute' these until just golden, reduce the flame and add the cooked vegetable matter. Toss together and heat about 5 minutes. Season with salt and pepper and serve. Hard-cooked eggs and anchovy fillets are a nice garnish arranged atop or alongside.

This treatment, by the way, makes many other strong-tasting vegetables more appetizing. Brussels sprouts, beet greens, kale, spinach and swiss chard are all tastier this way than if boiled or steamed and plopped on the plate.

Q: Of what use are lupini beans? Who grows them and why? I bought a jar of them recently; the label says they're tasty eaten cold as an appetizer or served like any other bean. I ate a few and found them salty, bitter and coated with a tough skin. Now the 79-cent jar is languishing in the refrigerator.

A: Lupini beans, also called lupin seeds, come from Lupinus albus, a member of Leguminosae, the legume family (to which all peas and beans belong). There are several hundred varieties of wild lupins (pronounced loo-pins); the bluebonnet -- the Texas state flower -- is one. Three or four species of lupins are grown throughout the world as green manure, cattle feed and human food. Lupins thrive even on poor soil. They fix atmospheric nitrogen and, plowed into the soil, enrich it when alternated with cash crops. Both the lupin plant and its beans are used in Australia, Poland and the Soviet Union as cattle feed. And the beans are consumed in Italy, Peru and Chile whole, ground into flour for bread or as a paste.

The bitterness of lupin seeds is directly proportional to their content of poisonous alkaloids. These range in concentration from 0.01 to 2 percent by weight. Alkaloids are a class of plant-synthesized drugs whose effects vary from simply bitter quinine (added to tonic water) to the moderately poisonous caffeine (found in tea, coffee, chocolate and colas) to the more poisonous solanine (found just under the skin of some green potatoes) to the very poisonous and narcotic lysergic acid synthesized by the rye mold, ergot. The alkaloids of the bitter varieties of lupin seeds rank close to solanine in potency.

For millenia, even the more bitter lupin varieties have been eaten by humans. In Roman times, lupin seeds were distributed to the poor. They have also been wartime rations during the hundreds of European conflicts since then. Lupin-seed eaters have avoided poisoning themselves by soaking and cooking the seeds.

This is possible because of the solubility of alkaloids in water. A three-hour soak removes most bitterness and saltiness. I do not know why the seeds you bought have been cooked in a brine. Perhaps during the thousands of years sans refrigerator, brining the soaked and cooked seeds and other beans was preferred to cooking them fresh every day. In a brine, they would keep in a cool place for weeks, even months.

Lupin seeds are nutritional equals to soy beans and are therefore among the most nutritious vegetables known. They are very high in protein -- 40 to 60 percent. Some varieties are also rich in oil and could be used to produce salad or cooking oil.

In Italy, lupin seeds are considered domestic fare, not something one would order in a restaurant. After soaking them (about 3 hours) to remove most of the bitterness and saltiness, Italians often cook them to soften the tough skins. Lupin seeds are delicious mixed with good vinegar, olive oil, chopped herbs, onions, fresh tomatoes and tuna. Like chickpeas, they retain an agreeable crunchiness. In some cities of Italy, roast lupin seeds are sold by street vendors. are nutritional equals to soy beans and are therefore among the most nutritious vegetables known. They are very high in protein -- 40 to 60 percent. Some varieties are also rich in oil and could be used to produce salad or cooking oil.

In Italy, lupin seeds are considered domestic fare, not something one would order in a restaurant. After soaking them (about 3 hours) to remove most of the bitterness and saltiness, Italians often cook them to soften the tough skins. Lupin seeds are delicious mixed with good vinegar, olive oil, chopped herbs, onions, fresh tomatoes and tuna. Like chickpeas, they retain an agreeable crunchiness. In some cities of Italy, roast lupin seeds are sold by street vendors.