Boil in salted water three or four big onions. Dry them. Put in a fireproof dish one ounce of butter and melt it. Cut your onions in small quarters and put them in the butter till they get a golden colour; then add two rashers of streaky bacon cut very thin. Cook in the oven for a quarter of an hour. Remove the dish and keep it aside till it is only tepid. Then add one beaten egg, a spoonful of cream, mix well together and put back in the oven till golden brown.