FRESH PASTA is one of those rare passions that is both sensual and practical. Not only does it taste good, it's cheap; at least when you make it yourself. The variety of pasta sauces is infinite and there could be no better vehicle for recycling leftovers, be they animal, vegetable or mineral.

Italian women routinely prepared the family's daily pasta with the help of only a rolling pin and a knife. Of course they had the time and the talent. Here (and over much of urban Italy) machines are invoked and the process becomes less one of technique than determination. There is a sacrifice in texture pasta purists say, but in essence they are dealing in nuances of taste. (Pasta purists, incidently, are becoming the greatest threat to honest enjoyment of food to appear since the heyday of the wine snob. The most outrageously bold of them are said to place individual hand graters before their guests so that cheese may be grated directly onto the pasta.)

Making it is our objective, but first take time for some research and a moment or two of self-appraisal.

But some fresh pasta (several sources are listed on Page E22), or beg some from a friend already bitten by the pasta-making bug. Cook it and acquaint yourself with the texture.Being told fresh pasta is "better" isn't enough. Unless you believe it, you won't bother after the first attempt or two. One possible comprise is to buy imported, dried pasta. It is far superior in texture to domestic supermarket spaghetti. Several sources for imported pasta are suggested below.

Now think about your cooking and eating patterns. Almost everyone loves pasta, yet many people avoid it because it attracts calories faster than honey draws a bear. (The multitude of calories aren't in the pasta, and needn't be in a pasta dish, but that is another subject.) Short of adopting Italian life style, many people just won't make pasta enough to justify the expense of yet another piece of kitchen equipment.

The price for economizing by making your own pasta will be about $50 for a good mechanical pasta maker and can be $150 to $250 or more if you decide to buy an electric machine. Clever cooks mitigate the cost by finding other uses for their toy. Among them: rolling out wonton skins, cracker dough and chocolate.

The expenditure of time depends on the quantity of pasta you make. After some practice there is no reason you cannot create, cook and serve pasta for two or four persons plus a simple sauce in an hour or less. A third hand is very helpful, however, when using the mechanical pasta maker and remember to put the cooking water on early.

Serve the pasta, bread, salad and some fruit or a prepared dessert and your menu is complete. Add cheese and a bottle of Italian wine and you'll be ready to sing an aria.

Shaped pasta, such as ravioli, capelletti and tortellini, is not for the novice. Standard pasta-making machines turn out flat pasta, though they provide a choice of thicknesses and width. These machines are a rarity among complex tools in that they follow operating instructions with remarkable fidelity.

For beginners the formula recommended by Marcella Hazan in her superb "The Classic Italian Cook Book" is a good one. For a two-person serving she recommends combining 1 large egg with 3/4-cup all purpose flour.

Make a mounded small ring of flour and place the egg in the center. Beat the egg well with a fork, then gradually incorporate flour from the ring. Once the egg has merged into the flour, use your hands to finish the job. Add another tablespoon or two of flour if the dough remains moist. (The dough may be made in a food procesor.)

To make enough pasta for three or four portions. Hazan calls for 2 eggs with 1 1/2 cups flour, and 3 eggs with 2 1/4 cups flour for five or six portions. She does not add salt or oil to the dough, although some cooks do. Also, lovers of rich, yellowish pasta will use several extra egg yolks and make their pasta by feel and touch rather than by formula.

Experienced home bakers may want to roll the dough out to a paper thinness with a thin, long rolling pin, wrap it up on the pin, remove the roll and slice along the roll at regular intervals (say 1/2 inch). Then unravel the pieces and hang them to dry.

If using a machine, keep the dough covered so it won't dry out. Break off a piece and work it through the widest setting of the rollers until it is smooth and satin-like, which may take 8 to 10 passes. Don't force too much dough into the machine. Hazan recommends lemon-sized pieces. Change settings and pass the sheet of dough through until it is as thin as you wish it to be. Place sheet on a table or hang on a rack (a broom hangle between two chairs is a popular jury-rigged rack; one of those folding wooden racks usually used for drying clothes is much safer.) Continue with remaining dough. Trim dough sheets to desired length (from 12 to 24 inches) and pass them through the cutting wheels of the machine.

Collect the strips and hang them, or spread them on a table until ready to cook. Unused pasta noodles need not be refrigerated though many cooks choose to freeze them. When dry they may be stored in a dry, cool place for several weeks.

Once you have your pasta, the ritual of preparation can begin. There are important rites to observe at every step, however. COOKING

It is essential to use a large quantity of water, three or four quarts. Bring the water to a boil covered. Add a generous amount of salt, 2 tablespoons or so. When it has dissolved, stir the water and add the pasta. Stir again to keep the noodles separate then cook uncovered until the water returns to a boil. Capture a noodle and bite it. If the center is still white, or if you can taste flour, the pasta isn't done. Fresh pasta cooks faster than commercial, sometimes in less than a minute after the boil. Al Dente means the pasta has reached a uniform texture, firm but only slightly chewy, that still provides some resistance to the tooth. fWhen the pasta has arrived at this state, turn off the heat and immediately pour a cup or two of cold water into the pot to stop the cooking. SERVING

Because pasta cooks so quickly and tastes best when severed immediately, it is a wise idea to prepare the vehicle of transportation to the table in advance With a meat sauce, you may want to serve individual portions topped with a generous dollop of sauce.But a good sized bowl or platter is almost essential if the pasta and sauce are to be tossed together. Pottery looks best, but any bowl will do. Begin to heat the sauce before cooking the pasta. bHave butter or oil, salt and pepper and garnitures such as chopped parsley or grated cheese close at hand. Warm the bowl with hot water or in a low oven.

Drain the pasta in a colander. Toss but do not rinse it. Dump it in the warm bowl atop a couple of tablespoons or so of butter or, oil and toss. Now add the sauce being careful not to drown the pasta. Toss again, season and sprinkle on the garniture then race for the table. Grated cheese, appropriate to all but a few fish and pasta recipes, should be there before you.

If you are serving a large group, consider making two batches remember to have two pots of water at the boil) and ordering your guests to eat as the pasta reaches them. Cold pasta has its place in a salad or as a morning-after snack, but tepid pasta is inevitably disappointing.

SEA BASS SAUCE: Clean and fillet a 1 1/2 to 2 pound bass (turbot, halibut or any white fish can be substituted). Chop the fillets into small bite-sized pieces and set aside.

Brown a finely sliced onion in 4 tablespoons olive oil, add 1 thinly sliced carrot and 1 celery heart cut in strips or finely chopped. Cook for a few minutes, until the vegetables are soft. Add 6 small fresh peeled tomatoes, or a can of drained plum tomatoes, chopped. Season with salt and pepper, a pinch of oregano and a few basil leaves.

When the sauce is thick, add the fish and cook over low heat for bout 20 minutes or until fish flakes. Add 6 ounces of dry white wine, reheat for a few minutes then serve atop hot spaghetti. Makes 1 to 6 servings. -- adapted from "Pasta," by Vincenzo Buonassisi

ROASTED PEPPER SAUCE: Roast 2 large red bell peppers and 2 large green peppers over direct heat or under a broiler until the skin is browned. When they are cool enough to handle, peel off the skins -- do not wash (some black specks will remain, but they are edible). Discard ribs and seeds and dice peppers. Wash 1 pound of fresh plum tomatoes (substitute with canned if unavailable). Discard hard portion near steam (if fresh) and chop. Peel and mince 1 onion and set aside.

Put tomatoes and peppers in a blender and puree. Set aside. Heat 2 tablespoons olive oil in a saucepan and add 1 clove of minced garlic. Add minced onion and saute until onion is transparent. Add the pepper and tomato puree and 1/3 cup fresh parsley (Italian parsley if available) and cook for 5 or 6 minutes. Season with salt and pepper to taste. Serve with fresh pasta. Makes 8 servings. -- Adaptd from "Naturally Italian," by Elisa Celli

TOMATO SAUCE WITH CHICKEN LIVERS: Melt 4 tablespoons butter in a large saucepan. Add one (1pound) can finely chopped plum tomatoes (including juice), 2 tablespoons freshly chopped parsley, 2 tablespoons sweet basil and season with salt and pepper. Blend throughly and simmer gently over low heat, adding liquid if needed. Cook until reduced and thickened (about 1 hour).

Lightly saute 1/2 pound chicken livers with 1 bunch chopped scallions, 2 cloves minced garlic in 4 tablespoons olive oil until golden brown. Add 1/4 cup white table wine, simmer 5 minutes, then add tomato sauce and blend throughly. Serve atop hot fresh pasta. Makes 2 cups. -- adapted from "Papa Rossi's Secrets of Italian Cooking," by Victor Bennett with Antonia Rossi