A LITTLE LESS than six years ago the first make-your-own convenience-food recipes ran in this newspaper. This is the ninth in an irregular, but ongoing series. Interest in these home-made convenience foods doesn't seem to wane. Whether it's how to make your own biscuit mix or chocolate chip cookie mix, help for hamburgers or shake it and bake it, there are the Food section's most frequently requested recipes; for a variety of different reasons.

Some cooks are looking for ways to save money; some are worried about the chemicals put in ready-made foods; some need to cut down on their salt intake; some feel foods made at home have more nutritional value; some believe homemade tastes better.

All of the reasons people give for wanting to make these foods themselves make sense.

Convenience foods are not necessarily that convenient. And you have to look at the trade-offs: Is the cost of these products worth the amount of time saved; how much nutrition are you giving up for the time saving and at what price; how many unknown ingredients are you ingesting in the interests of saving time?

Certainly some of the recipes below require more effort on the part of the cook than buying the packaged mix. But mixes like those for the cake or the Italian seasoning can be done when you are not tired or in a hurry. Then they can be stored as any store-bought mix would be. In experimenting with these products over the years I have discovered that even without the preservatives most of them have an extremely long shelf life if stored as directed. I have kept cookie, cake, biscuit and muffin mixes for six and eight months.

Convenience foods are not all the put-it-away-until-you-need-it variety. Recipes like the Tuna Stroganoff are meant to be used as made. But it takes so little extra time to put them together yourself. The minute or two, if that, is worth it every way you look at it.

Try some, you'll like them.

Betty Crocker calls them Hamburger Helpers. But you can help your own hamburgers, or tuna, (see next recipe) with half the number of ingredients for less than half the price. You can make this chili version without the soybean oil and cornstarch, both of which add unnecessary calories, without the sodium sulfite or BHA used to preserve freshness, without the sugar and without all the salt. There's so much salt in the commercial version that a single serving has half of the amount a normal person needs. CHILI HELP FOR HAMBURGER (5 small servings) 1 pound ground beef 4 cups water 1 cup elbow macaroni 2 tablespoons minced dried onion 1/2 teaspoon minced dried garlic 1 to 1 1/2 teaspoons chili powder 1/3 cup tomato paste Salt and pepper to taste

Brown the ground beef in large skillet. Pour off fat. Add remaining ingredients, seasoning to taste with salt and pepper. Stir, bring to boil and simmer uncovered for about 15 minutes, until it is a thick as you like.

The first time I made this, a year ago, it cost 62 cents and Tuna Helper was selling for 89 cents. Today both cost more but it's still cheaper to make it at home yourself with real ingredients. HELP FOR TUNA STROGANOFF (5 small servings) 2 cups egg noodles 3 1/2 cups water 6 1/2 or 7 ounce can tuna, washed and drained 2 tablespoons minced dried onion 1/4 teaspoon minced dried garlic 3 tablespoons sour cream 1/2 cup grated cheese Salt and pepper to taste

Combine water, noodles, drained tuna, onion and garlic in large skillet. Bring to a boil; reduce heat and simmer, uncovered, about 7 minutes, until water has evaporated. Stir; reduce heat and then stir in sour cream and cheese. Continue to stir and mix well until cheese melts. Serve.

I've tried this recipe with white flour and whole wheat flour. The buckwheat flour has such an insistent flavor it overpowers the others so if you like the added nutrition of the whole wheat flour you might as well use it. BUCKWHEAT PANCAKE MIX (Makes about 4 dozen 3-inch pancakes) 1 cup light buckwehat flour 1 cup whole wheat flour 2 teaspoons baking powder 1 teaspoon baking soda 2 teaspoons sugar 1 teaspoon salt

Mix ingredients together well and place in tightly covered container in cool, dry place. Mix will keep at least eight months if properly stored. To make about 20 pancakes: 1 heaping cup buckwheat pancake mix 1 egg, separated 2 tablesppons melted butter 1 cup buttermilk or sour milk*

Combine the mix with the yolk, butter and sour milk and mix well. Beat the egg white until stiff and fold into batter. Cook on hot griddle or in heavy skillet which has been lightly greased. You will need to grease the griddle lightly every now and then, depending on how well seasoned it is. Brown the pancakes on one side. Turn when edges begin to brown and bubbles from on the surface; bake until golden on second side. Serve with butter and maple syrup.

*To sour milk: Have 1 cup of milk at room temperature. Place 1 tablespoon of lemon juice or white vinegar in bottom of measuring cup. Fill the cup with the milk to 1 cup level (you will have 1 tablespoon of milk leftover) and stir. Let stand about 5 minutes until milk clabbers, i.e., a curd froms in the liquid.

It takes about 10 minutes to make this cake mix. When you are ready to make a cake, it will take five minutes. That's a minute or two longer than it takes using a box of cake mix. Baking time is approximately the same. SPICE CAKE MIX (Makes 6 single layers) 8 cups unbleached white flour 2 1/4 cups sugar 2 1/2 teaspoons baking soda 2 tablespoons baking powder 3 tablespoons ground ginger 3 tablespoons cinnamon 1 teaspoon ground cloves 1 tablespoon salt 2 1/4 cup solid shortening

Sift dry ingredients together twice. Cut in shortening with pastry blender or two knives until mixture is completely blended. Store in airtight container in cool place. Mix keeps at least three months To make a single-layer cake: 2 cups mix 1 beaten egg 1/2 cup molasses 1/2 cup boiling water

Place mix in a mixing bowl. Combine beaten egg, molasses and boiling water. Beat into dry ingredients until well blended. Pour into greased and floured 8-inch square baking pan and bake at 350 degrees for 30 to 35 minutes. Cool and frost as desired.

A cream cheese frosting is good with this cake.

This is a medium cream sauce base that has been turned into a cheese sauce with the simple additon of dry grated parmesan cheese. With a sauce like this you don't have to buy those frozen vegetable-in-sauce combinations that cost so much. You can also use the sauce on pasta or rice CHEESE SAUCE MIX (Makes 10 1/2 cups mix) 1 cup flour 4 cups nonfat dry milk 3 1/2 cups dried grated parmesan cheese 2 teaspoons salt 2 teaspoons paprika 1 teaspoon nutmeg 1 cup butter or margarine, cut in pieces

Mix together flour, dry milk, cheese, salt, paprika and nutmeg. Cut in the butter with fingertips or pastry blender until mixture is thoroughly mixed and crumbly. Store in airtight container in refrigerator or freezer. Mixture doesn't freeze solid so it is easy to spoon out the amount you need. To make one cup sauce: 1/2 cup cheese sauce mix 1 cup milk

Blend mix and milk together in saucepan. Cook and stir over low heat, until sauce comes to boil. Simmer gently for a minute or two, to cook the flour.

Note: 2/3 cup water can be substituted for 1 cup milk.

If you keep this seasoning around, you can throw it into tomato sauce for a very fast spaghetti sauce; add it to oil and vinegar for a dressing on greens or over broccoli or green beans. You can even mix it with cream cheese to make a speedy spread for fast hor d'oevures. ITALIAN SEASONING MIX (Makes scant cup) 3 tablespoons dried oregano leaves 2 tablespoons dried basil 2 tablespoons dried thyme 2 tablespoons dried marjoram 2 tablespoons dried parsley 4 teaspoons garlic powder 4 teaspoons onion powder 2 teaspoons coarsley ground pepper 2 teaspoons salt

Mix ingredients together and store in airtight container in cool, dry place.

Allow 1 to 2 tablespoons mix for a 29-ounce can of tomato sauce; 2 to 3 teaspoons mix for 1 cup oil and vinegar dressing; 1/2 to 1 teaspoon for 3 ounces of cream cheese.

One of the nicest ways to make use of the fresh herbs of summer well into the winter is to make flavored vinegars and butters. Recipes are often far more complex than they need to be. You need freezing space for herb butters but not for herb vinegars. HERB BUTTER (Makes 1 cup) 1 cup butter, softened 1 cup minced fresh tarragon, basil, oregano, thyme or marjoram 4 teaspoons fresh lemon juice Salt and pepper to taste

Place ingredients in food processor or electric mixer and blend until leaves are thoroughly mixed with butter.

Use on bread, fish, meat or poultry, vegetables. Use to sautee vegetables.

If using in cooking or serving on hot food, it isn't necessary to defrost the butter before using.

No need to boil or steep herbs in vinegars for a long time. As a matter of fact, as one herb-vinegar expert has pointed out, if you boil the herbs with the vinegar you increase the acidity by evaporating some of the water in the vinegar. HERB VINEGAR (Makes 1 quart) 1 quart distilled white, cider, rice wine, red or white wine vinegar 4 ounces of fresh herbs such as tarragon, thyme, sage, marjoram, dill, basil, washed and drained

Place the vinegar in a large crock or other nonmetal container or in several small containers. Add the herb of your choice, stems and all. Allow to sit for three days in a warm, dark place. After three days check the vinegar for flavor. Keep checking until the vinegar has developed sufficient flavor, but do not allow to sit too long or the vinegar can become bitter.

Strain vinegar into clean bottles and close tightly. Store in cupboard.