If you want to make it as even a marginal cook, you must acquaint yourself with the underbelly of cooking.

This is what professionals call "prep." It's what people who don't cook call good reasons not to -- chopping onions, washing

lettuce, peeling potatoes.

Summed up, I get Seven Immortal Chores.

They're immortal because no machine or shortcut has managed to kill them off. They're chores because they're required, repetitious and often disagreeable.

What follows are the everyday un-glamorous backstage moments that support your simplest kitchen efforts. On the plus side, the better you get at these, the quicker you'll get them over with and the less they'll faze you. (Note: Most require two deadly sharp knives -- one chef's knife 8 inches or longer and one paring knife -- plus a wooden or plastic cutting board.) The seven chores:

1. Mincing garlic

2. Chopping parsley

3. Slicing mushrooms

4. Seeding and chopping tomatoes

5. Chopping onions

6. Peeling potatoes

7. Washing lettuce

Here's how to do them, and do them right.

Chopping styles

* One-hand hold. Your dominant hand grasps the knife from above, between blade and handle, while your other hand steadies the food being cut and feeds it across the cutting board to the knife.

* Two-hand hold. Your dominant hand grasps the knife's handle but holds the knife parallel to your body with the blade resting on the cutting board. Your other hand puts pressure on top of the knife's blade near the tip. Seesaw the handle up and down, while keeping the point in place so it can pivot on the board. Work the handle across the food in a fan shape. Gather the food into neat piles as you go.

Mincing garlic

First, learn the lingo. A clove of garlic is one crescent-shaped section. To free garlic cloves from their bulb, bang the whole bulb with the flat side of the blade, or whack it with a jar or small skillet. Whack individual cloves the same way. The papery peel will burst. This avoids hand-removal of the peel, which sticks to human skin. Cut off the brown root tip.

To chop: With a sharp knife, cut a clove into lengthwise slivers. Now cut across the slivers with slices close together to make small pieces.

To mince: Switch to a chef's knife and the two-hand hold. Rock the knife over the chopped garlic until pieces are very fine. Gather the garlic into a small pile as you go.

To avoid peeling and chopping garlic and still have it peeled and chopped, "roast it," says Tish Parmeley, food director of the Stinking Rose restaurant in San Francisco.

Set an entire bulb in the oven for an hour at 350 degrees. When it's cool, squeeze out the garlic, which has turned to a paste. The Stinking Rose uses the paste to thicken soups, sauces and gravies. You can spread it on slices of toasted baguette.

Another way to avoid chopping is to use a garlic press or mini-chopper. Garlic lovers can avoid the frequency of garlic prep with this tip: Plunge peeled garlic cloves briefly in boiling water; chop and store in olive oil in the refrigerator.

Chopping parsley

Nothing completes the taste or appearance of food like fresh chopped parsley. Once you master parsley, you can chop or mince any fresh herb -- cilantro, mint, dill, basil, oregano.

Chef Brian Glover washes parsley and shakes it out. He lines up the leaves, then twists them compactly so they'll fit under his fingers. In his other hand is a sharp, 8-inch chef's knife. He makes smooth cuts close together over the leaves until he comes to the stems, then stops.

Switching to a two-hand hold, Mr. Glover attacks the leaves in the opposite direction, to make them even smaller. Finally, he scoops the blade of the knife underneath his parsley pile and turns the whole thing over and chops again.

Dull knives won't serve you well when chopping herbs. "They crush the cells, and the parsley won't last as long," Mr. Glover says. "In one day it can smell like the day after you mow your yard."

Slicing mushrooms

Anyone who likes mushrooms uses fresh ones often. How they should be washed is controversial. Mushrooms contain water. Heat draws out this water and can make mixtures watery. Washing mushrooms adds to that excess liquid. Wiping them clean with a dry paper towel is sometimes recommended. Excuse me, but mushrooms grow in -- well, sterile manure -- and you may doubt that paper towels can get into all the nooks and crannies.

Executive chef David Burdette goes through 20 pounds of mushrooms a day. They are washed well in water; then they're all chopped by hand with a sunny attitude.

Mr. Burdette uses a 10-inch chef's knife and cuts off the stems flush with the bottom of the mushroom caps. He holds the knife in his dominant hand while clinging to the mushroom caps, gills-side down, with the other. He cuts the caps into thick slices, gives them a half-turn and slices them in the opposite direction. Finally, he uses the two-hand hold to chop the mushrooms just a little finer.

Mr. Burdette cautions about trying to chop too many mushrooms at once. "You can't just put a whole box of mushrooms on a cutting board and start chopping. You'll have mushrooms all over the floor."

Chopping tomatoes

Salsa is made with tomatoes hand-chopped into cubes just a little larger than 1/4 inch.

Despite sales of "tomato" knives with serrated blades, chef Matt Martinez says a thin, smooth blade works best. "The blade's got to be real sharp and real thin to pierce the skin, and deep in back and narrow in front."

He takes out the core and cuts the tomato in half at its equator. He makes many slices over each half, skin side up. Next he runs the knife under the tomato, flips it over and flattens it. To finish chopping, he uses the one-hand hold and quickly slices in the opposite direction while feeding the tomato under the blade with his other hand.

Chopping onions

People have tried all sorts of ways to chop onions without really chopping them. This won't be reassuring: There are no shortcuts. A food processor chops onions into irregular brown-edged pieces easily spotted as the work of a machine. Besides, if you use a food processor, you have to clean it.

Practice holding the onion: If right-handed, hold the onion with left fingertips curled under. Notice a flat barrier forms across the fingers between the first and second knuckles. This area is a guide for the knife to lean on. This may feel uncomfortable at first, but it is safe and not nearly as uncomfortable as losing a finger. The bigger the blade, the better you can feel it.

The first cut: If you cut an onion in half lengthwise from the stem to the root, it won't roll. Set each half flat-side-down on the cutting board.

To dice or cube: Aim the knife over the onion-half at the root. Make slices to, but not through, the root all the way across the half. The root holds together layers that have a tendency to slip.

Turn the knife blade parallel to the counter, steady the top of the onion with your palm and make horizontal slices. Again, go to, but not through, the root, making about two or three cuts. You'll see a grid forming on the side of the onion. Finally, go back to the top of the onion and slice the grid. Diced onions will fall onto the counter.

To mince: Do as above, but make your cuts closer together. Switch to the two-hand hold, and with the tip of the knife steady, rock the blade over the cutting surface. Most of the mincing action will take place under the middle of the blade.

With practice, chopping onions will become a minor episode on the way to a greater good -- such as dinner.

Peeling potatoes

Potatoes you'll eat with the skins on need only washing and a scrubbing with a vegetable brush. But if you want them peeled, you'll have to spend some time over the sink with the potatoes and a swivel-bladed potato peeler.

The best way to peel a potato is to brace it on the edge of the sink with one hand and hold the vegetable peeler in the other. In quick flicks, peel off pieces directly into the sink, where, with luck, you've got a garbage disposal.

Potatoes darken when their white flesh is exposed to air. If you are slow at peeling, the first potatoes may darken before you've finished peeling the last. So as each potato is peeled, drop it into water.

Washing lettuce

Home cooks wilt at the thought of making salad because lettuce-washing is drudgery. Still, it is an art that starts with one strong belief: There's always dirt in lettuce.

Discard the outer leaves for the Caesar and other salads. Next, cut it up, then thrash through a sink to rid it of sand or grit. To keep it crisp, store in ice water.

All that crisp lettuce is, of course, sopping wet. It has to be dried so dressing won't slide off.

If you eat a lot of salad, or if you want to make this chore as easy as technology has taken it to date, get yourself a salad spinner. Washed, spin-dried lettuce will keep two to three days in a covered container in the refrigerator.