Spread one-third of the onion over the bottom of a casserole. Add one-third of the apple slices, then one-third of the mushrooms and bacon, then half the liver. Season well. Continue making layers in this way.

Pour in the consomme and spread the tomatoes over the top.

Cover tightly and cook in the oven for 1 1/2 hours. Serve garnished with chopped parsley.

To use lower-calorie ox or pig liver, cut it in slices and soak overnight in skimmed milk with a teaspoonful of bicarbonate of soda; it will be much improved.