Every housewife faces the problem of "left-overs." To utilize and prepare them into satisfactory dishes requires more skill and inventiveness than to cook the raw food, and this branch of cookery is an art in itself. The thrifty home-maker uses all the left-overs. Living has been much too high for the average person to ignore this type of cookery.

Food can so easily be spoiled by reheating. Take meats for example. A tender piece of roast beef reheated for ten minutes will be tough. This applies to almost all cooked meats. If sliced very thin and hot sauce or gravy poured over the slices, the meat will be tender; but if added to the hot gravy in an attempt to reheat it will invariably toughen. Meat must be cooked a long time when reheating if it is to be tender, the theory being that it will toughen at first, but will become tender by long, slow cooking. For this reason the covered casserole dishes have become almost indispensable.

A casserole is used for cooking foods that require slow cooking for either a short or long period. The dish is covered to keep in all the steam, and to retain flavor. Dicing food takes more time than chopping or putting through a food grinder, but if one has the time, diced meat will present a much more attractive appearance, as well as being more palatable. Diced meat or fish may be combined with a white sauce, adding cubes of cooked potatoes, several tablespoons of cooked peas and diced carrots. If meat is used, salt, pepper and onion juice can be the seasoning; if fish, add a little lemon juice also, or a finely chopped sour pickle. Or add the diced meat to a tomato sauce, seasoning well with onion and chopped green peppers, adding six or eight ripe or green olives. A meat pie is always acceptable. Dice meat, add to thickened, well seasoned gravy or sauce, adding cooked potatoes cut in cubes, and small boiled onions and any other left-over vegetables, such as peas, carrots, turnips or cauliflower. Place in a casserole or baking dish. Make a plain pie crust or biscuit dough for top and bake in a moderately hot oven.

This may be prepared in the morning, and the crust made, but not added until the pie goes into the oven.

Smaller quantities of left-over meat or fish may be chopped and made into souffles, timbales or croquettes, or added to a well-seasoned white sauce and served on toast, or in ramekins or a baking dish, the top covered with buttered crumbs and then browned in the oven. The white sauce, made of butter or substitute and milk, supply additional food value to take the place of the smaller quantity of meat or fish.

One most important factor in the success of these dishes is in careful preparation. All bones, gristle, skin or tough, undesirable portions should be removed and discarded. If there are large meat bones, as in a roast of lamb, these may be broken - adding two or three cupfuls of cold water, also an onion. Simmer for an hour or more and use as a base for gravy or sauce.

A cupful of chopped meat or fish will make a souffle, croquettes, timbales or creamed meat in ramekins for four persons.

Left-over vegetables can be reheated in a white sauce, used for cream soups or chowders; scalloped, made into au gratin dishes, added to a fritter batter and fried in deep fat or used in salad.

Almost any combination of vegetables makes an attractive salad, providing it is accompanied with a well-made salad dressing. The left-over breakfast cereal may be molded, sliced, dipped in flour and fried a delicate brown, or half a cupful may replace the same quantity of flour in the breakfast griddle cakes or muffins; any fresh or cooked fruit can be mashed and poured over molded cold cereal for the children's dessert.

Stale broken pieces of bread may be dried in a very slow oven, then rolled or put through the food grinder and stored in covered fruit jars. To be used in scalloped dishes, to bread cutlets, fish or croquettes. Or cut into very small cubes, dried in a slow oven for croutons for soup; made into dressing for stuffed poultry, meat, fish, tomatoes or eggplant. Any of the bread puddings are palatable, provided too much bread has not been used. The old-fashioned custard bread pudding should not be made just to save bread, for that would not be an economy, as the other ingredients needed are too expensive merely to use up left-overs of bread.

Small portions of cooked or raw tomatoes may make savory sauces.

Sour milk should never be wasted. It can always be substituted for fresh milk in flour mixtures, using one-half teaspoonful of soda to each cupful of sour milk, omitting the baking powder; or the sour milk can be made into cottage cheese.

All pieces of beef or chicken fat should be cut fine and carefully rendered to be used for frying. Fat left from frying bacon or ham should be saved, but kept in a separate jar, as the smoked flavor is not desirable for all frying.

Left-overs of fruit may be combined and used for salads or for dessert. Stale cake may be served for pudding, with the addition of a custard or chocolate pudding sauce; or the cake may be cut in finger lengths and used for charlottes or charlotte russe.

The greatest care should be given left-overs, so that they will be in proper condition to use later. Jelly glasses with covers are convenient for small portions of vegetables or fruit.

The use of left-overs is unlimited, and while such cookery requires both consideration and time, the results will amply repay for the additional labor.