Arthur Grosser thinks the most important thing about cooking (besides eating) is having control in the kitchen. "You can learn to manipulate things in the kitchen with freedom and confidence," says the McGill University chemistry professor cum cookbook author.

Grosser wrote "The Cookbook Decoder" to help explain the rather simple scientific theories upon which cooking is based. For instance, many recipes tell you not to add fresh pineapple to gelatin salads. Fresh pineapple contains an enzyme, bromelin, which breaks down long chains of protein and thus prevents the gelatin from setting.

Knowing the principle, says Grosser, allows you to fit the recipe to your own needs. If you want fresh pineapple in the salad, all you need to do is poach it, which inactivates the enzyme. But knowing the principle also allows you to apply it elsewhere. Marinating meat with fresh pineapple juice or chunks allows the same enzyme to break down the tough proteins, thus tenderizing the meat. Indeed, bromelin is the substance found in many commercial meat tenderizers.

Knowing principles not only keeps you in control of the kitchen, says Grosser, it keeps you in the kitchen and not making special trips to the store. When a recipe calls for wiping the exposed meat of an avocado with lemon juice and you're out of lemons, why run to the store? If you know the principle, you know that the avocado meat will turn brown when exposed to air and that acid substances prevent this. Substitute orange juice, vinegar, mayonnaise or even a little cream of tartar mixed with water.

Grosser teaches this theory through prose, recipes and a series of kitchen experiments called "autodemonstrations," which show the application of a certain cooking theory. And he makes some interesting points, a few of which follow:

* Of garlic flavor: Garlic contains two substances that must combine to create the garlic flavor. They combine only when cell membranes break, which is why a cook is asked to chop or mash the garlic clove. One of these substances is an enzyme. Enzymes are destroyed by high heat. So it stands to reason that if you put an unmashed garlic clove in a dish that is to be heated, the garlic flavor will be much less intense -- hence the ability to make a chicken recipe using 30 cloves of garlic.

* Of egg white foams: Cream of tartar helps form stiff egg whites by changing the electrical charge of the molecules so they are attracted to each other. Cream of tartar is acid; egg white protein is alkaline. So if you're in the middle of the meringue for your lemon meringue pie and you discover you're out of cream of tartar, add a touch of vinegar or lemon juice.

* Alcoholic drinks: When sweetening libations, add the sugar to the water-based component of the drink. Sugar is 200 times less soluble in alcohol than water, says Grosser. "If you are making a strong drink, with not much water in it, use super-fine sugar . For a real killer, your only solution is to use a simple sugar syrup."

* Browning: Cooking meat browns when protein combines with sugar under high heat. To get a nicely browned coating on the surface of meat, rub the surface with sugar-containing sauce (such as barbecue sauce or ketchup).

Grosser uses a few of his principles to enhance lamb with an Indonesian-style marinade. But the only principle behind an express lane dinner is the need for eight items (more or less, depending on the market) in addition to the flour, sugar, salt, pepper and oil and/or butter that you should already have at home.

EXPRESS LANE LIST: Tender lamb or pork, peanut butter, soy sauce, sherry, lemon juice, rice, green beans, marinated artichoke hearts. INDONESIAN SKEWERED LAMB (6 to 8 servings) 2 to 2 1/2 pounds tender lamb (cut from the loin or leg), or pork, cubed 1/2 cup peanut butter 1/2 cup soy sauce 1/4 cup dry sherry 1/4 cup lemon juice 2 tablespoons sugar

Cut lamb into 1- to 2-inch cubes. Place in a large bowl. Combine remaining ingredients in saucepan with 1/2 cup water. Heat and stir until smooth. Pour over lamb. Allow to marinate 3 hours if possible, or at least while you prepare the charcoal (if desired), rice (according to package directions) and marinated green beans. Skewer the cubes and cook over charcoal or on a rack under the broiler, turning often, until browned on all sides and done to taste.

From "The Cookbook Decoder" GREEN BEANS AND ARTICHOKES (6 to 8 servings) 1 1/2 to 2 pounds fresh green beans 11 1/2 ounces marinated artichoke hearts Salt and pepper to taste

Trim and wash green beans. Cook, covered, in a little boiling water until just tender (12 to 15 minutes). Drain and rinse with cold water. Place in bowl with artichoke hearts (including the marinade) and cover. Chill. Before serving, salt and pepper to taste.