WE ARE, I believe, on the edge of an important new phase in America's tenuous and often reluctant relationship with sophisticated eating. Those with gastronomic ambitions are beginning to believe that you can serve American food without fear or loathing. They are bringing home, so to speak, the techniques and taste sensibilities they have picked up in culinary travels through France, China, Italy and other countries. They, along with others who have never developed an expatriot's recipe repertory, are retreating from ostentation and excess and searching for preparations that are simple, real and celebrate freshness or the mood of the season.

Enter Fannie Farmer. Not the stern-faced taskmaster who guided the Boston Cooking School at the turn of the century, but a modern Fannie Farmer. Her name is Marion Cunningham. She, too, is a cooking teacher with pulled back gray hair, but her style is thoroughly contemporary, thoughtful and cosmopolitan. Four years ago Knopf and the Fannie Farmer Corporation charged her with the responsibility of revising and updating Miss Farmer's classic 1896 cookbook. Now, at a ripe moment, the task is done and the book is available for $12.95.

It's no longer the Boston Cooking-School Cook Book, Cunningham explained during a visit last week. "My hope is that this will be a basic American cookbook," she said. "I wanted a voice to be there, a personal voice speaking from a kitchen. I hate those institutional books. Second, by presenting recipes for what is being cooked, not what people might cook, I tried to appeal to anybody who wants to go into the kitchen and be a serious cook. That is -- what we have available -- is fine."

Fannie Farmer's book went through 11 revisions, the last coming in 1965. Cunningham worked with four: the original, the 1909, 1930 and 1965 editions.

"The changes weren't very dramatic until the last one," she said. "Then post-World War II kitchen influences (such as prepared foods and time-saving gimmicks) were incorporated. I can't help being an advocate of fresh foods. I decided not to use ersatz goods, to drop many of the gelatin desserts and use true fruit juices. There are recipes for tacos and cioppino. All the vegetables and fruits are listed seasonally and with descriptions of how to judge them in the market. Baking and yeast breads have been emphasized. There were 12 fish recipes in the 11th edition, now there are 33. We dropped the section on cocktails and added material on wine, tea and coffee."

Cunningham said research led her to the conclusion that meat and poultry roasting charts are obsolete, that cooking information provided by the government "isn't very good because it is so conservative." The Knopf "Fannie Farmer," she said, "does contain new information" as well as new and modernized recipes. But it was also a work of preservation. Many of the original recipes are there, unchanged or only slightly altered.

"Recipes are like clothing," she said, "the quality of the fabric remains the same, but from one era to another the skirts go up or the skirts go down."

Here, for example, is what the new book has to say about mashed potatoes: "Don't try beating potatoes in a food processor.The fast, spinning motion will develop the gluten in the potatoes and turn them into a gray, sticky mass. You can use an electric beater if your potatoes are mealy -- russet or Idahoes." The tools mentioned in the original were a ricer and a fork.

On the other hand, to read the recipe for Boston Baked Beans in the original and compare it to the new reproduced on Page E21, is to realize something has been lost as well as gained. One cannot but miss comments such as, "Drain beans, throwing bean-water out of doors, not in sink," or "The fine reputation which Boston Baked Beans have gained, has been attributed to the earthen bean-pot with small top and bulging sides in which they are supposed to be cooked. Equally good beans have often been eaten where a five-pound lard pail was substituted for the broken bean pot."

Cunningham credits Knopf's Judith Jones and James Beard for bringing her and Fannie Farmer together and guiding her along the way. Food writer Jeri Laber became involved, too. "At times during the past four years, I'd wonder what will become of all this, will it live up to what I hope for?" she said. "I was a novice. I didn't know what I had. All I knew was I had 1,893 basic recipes. Judith could see the finished whole and James was wonderfully helpful. 'Remember, you're Fannie Farmer.' he'd say when I was being indecisive."

She is modest about her own credentials. "I'm half-Italian," she said with a smile. "That sort of gets you right into it. I love to eat, like to read about food and have always been gregarious. With those basics, it just naturally follows that a woman, or a man, is going to cook." She began teaching nine years ago and has taught with Beard or on her own in New York, Italy and at her home outside San Francisco.

Her observations add up to a formula for modern living that is relaxed if not alid back. "Our life has moved from the parlor into the dining room and kitchen," she said. "It's a great loss when people stand at the refrigerator door and 'feed.' A communal gathering with food is important. To provide food that is good should be like providing a gift. We shouldn't feel it necessary to impress our family and guests. The key to eating better in this country is using good products.

"I also hope people lose their timidity in the kitchen and taste critically, not just make recipes by rote. That's the fastest way to learn how to cook well.

"One day a student commented that a cake I had made was not uniform. 'No,' I told her, 'I really don't want that. The cake was made in this kitchen by one cook. It shouldn't look like all the other cakes." OLD-FASHIONED BEEF STEW (4 servings)

A stew you will serve in soupbowls: dark-brown beef and vegetables in lots of rich gravy. 1/3 cup flour 1 teaspoon salt 1/4 teaspoon freshly ground pepper 2 pounds stewing beef plus bones 4 tablespoons shortening 1 tablespoon lemon juice 1 tablespoon Worcestershire sauce 1 large onion, sliced 2 bay leaves 1/4 teaspoon allspice 12 small carrots, trimmed and scraped 12 small white onions, trimmed 8 small new potatoes, peeled

Mix the flour, salt and pepper and roll the beef cubes in the mixture. Shake off excess. Melt the shortening over high heat in a Dutch oven or heavy-bottomed pot with a cover. When the fat is very hot add the beef, about 5 or 6 pieces at a time so as not to crowd them, brown on all sides and remove. When the last batch of meat is a richly dark color, return all to the pot and pour on 4 cups boiling water. Stand back when you do it, because it will spit and sputter. Stir and add the lemon juice, Worcestershire sauce, onion, bay leaves and allspice. Lower the heat, cover and simmer for 1 1/2 to 2 hours, or until the meat is tender. Add the carrots, white onions and potatoes and cook another 20 to 25 minutes or until they can be pierced easily with a fork. OLD-FASHIONED FISH CHOWDER (10 cups)

Use the head and bones from the filleted fish to make a rich fish stock fro this chowder. If you wish, let the chowder mellow in the refrigerator for a day before you eat it. Serve it with common crackers. 2-inch cube salt pork, diced small 2 onions, thinly sliced 3 medium potatoes, peeled and diced 4 cups fish stock or clam broth or juice 2 pounds fillet of cod, haddock, or any firm white fish 2 cups cream or milk 2 tablespoons butter Salt Freshly ground pepper

Cook the salt pork very slowly in a small skillet until the fat has melted and the scraps are brown. Strain, setting aside the crisp scraps, and put 2 tablespoons of the fat in a soup pot. Heat the fat, add the onions, and cook over low heat until golden. Stir in the potatoes and toss until well coated. Add the fish stock or clam liquid. Cut the fish in chunks, add it to the pot and simmer, partially covered, for about 15 minutes, or until the fish is cooked through and the potatoes are tender. Stir in the cream or milk and heat slowly without boiling. Add the pork scraps. Just before serving, stir in the butter, add salt and pepper to taste, and heat until butter melts. CONNECTICUT FISH CHOWDER (11 cups)

Omit the cream and substitute 4 cups canned tomatoes, undrained. If you wish, you may add 1/2 teaspoon dried marjoram or thyme along with the tomatoes. BOSTON BAKED BEANS (8 servings) 2 cups navy beans, small white beans or Great Northern beans About 1 teaspoon salt 1/4 pound salt pork 2 teaspoons dry mustard 5 tablespoons dark brown sugar 4 tablespoons molasses

Wash the beans. Soak overnight. Add salt, stir and drain, reserving the liquid. Preheat the oven to 300 degrees Farenheit. Cut off a third of the salt pork and place the piece on the bottom of a bean pot. Add the beans to the pot. Blend the mustard, brown sugar and molasses with the reserved bean pork and place on top of the beans. Cover and bake for about 6 hours, adding water as needed. Uncover for the final hour of cooking so the pork will become brown and crisp. Taste and correct seasoning. STUFFED ONIONS (4 servings)

Large round Spanish onions that range in color from yellow to red are ideal for this dish. You could use tongue or corned beef instead of ham -- any tasty cooked meat. 4 large onions 6 tablespoons butter, melted Salt Freshly ground pepper 1/2 cup coarsely chopped cooked ham 1/3 cup freshly made bread crumbs 1 1/2 teaspoons finely chopped parsley 1/4 teaspoon nutmeg 2 tablespoons dry sherry

Preheat the oven to 300 degrees Farenheit. Butter a casserole or baking dish large enough to hold the onions. Put the onions in a pan of boiling water to cover, and parboil for 10 minutes. Drain and refresh under cold water. Scoop out the centers, but leave a sturdy shell. Brush the insides with a little of the melted butter, and sprinkle with salt and pepper. Set aside. Combine the ham, crumbs, parsley and nutmeg in a small bowl, add salt and pepper to taste, and toss until mixed well. Divide the ham filling and stuff the four onions. Add the sherry to the remaining melted butter, and pour over each of the onions. Cover and bake for about 1 hour or until tender. BAKED RICE PUCCING (6 to 8 servings)

This bears no resemblance to the standard cafeteria version. Long, slow baking gives the rice a golden color and a thick creamy texture. Some purists don't even like the addition of nutmeg, but it does give the pudding a lovely flavor. Serve warm or cold, with heavy cream. 4 cups milk 1/2 teaspoon salt 2/3 cup sugar 1/2 teaspoon nutmeg (optional) 3 tablespoons rice

Preheat the oven to 300 degrees Farenheit. Put all the ingredients in a buttered baking dish and stir to blend. Bake for 3 1/2 hours, stirring three times during the first hour of baking so the rice doesn't settle. RAISIN RICE PUDDING -- Add 1/2 cup raisins to the ingredients. CHOCOLATE RICE PUDDING -- Add 2 ounces melted unsweetened chocolate to the ingredients. CHOCOLATE CAKE (Two 8-inch round layers)

A fine-grained, tender cake -- ice water is its secret. If you wanted a chocolate cake for a birthday, this would be the one to pick. 2 ounces unsweetened chocolate 1/4 pound butter 1 1/2 cups sugar 2 eggs 2 teaspoons vanilla 2 cups cake flour 1 1/2 teaspoons baking soda 1/2 teaspoon salt

Preheat the oven to 350 degrees Farenheit. Butter and lightly flour two 8-inch round cake pans. Melt the chocolate in a small pot or bowl over simmering water, set aside to cool. Cream the butter, slowly beat in the sugar, and beat until light. Add the eggs and the vanilla, mixing well. Add the chocolate and combine thoroughly. Mix the flour, baking soda and salt together, add to the first mixture, and blend. Add 1 cup ice water and beat until smooth. Pour the batter into the pans and bake for 25-30 minutes, until a toothpick comes out clean. Cool in the pans for 5 minutes before turning out onto racks. Frost with Portsmouth or Creamy Chocolate Frosting. PORTSMOUTH FROSTING (Makes about 1 3/4 cups) 4 tablespoons melted butter 1/4 cup cream 1 teaspoon vanilla or rum About 3 cups confectioners' sugar

Mix the butter, cream and vanilla or rum together in a bowl. Slowly beat in the sugar until thick and creamy. This is enough to fill and frost an 8- or 9-inch two-layer cake.