Peel large or medium sized onions in warm water to prevent the volatile oil from affecting the eyes, place them in a baking dish with butter enough to baste them well, and bake three hours, when they will be brown and tender. Fremove them on to a serving dish, pour hot water into the baking tin, and with a wooden spoon rub off all the dark brown caked juice, thickening if liked with a little flour, in which case the tin must be placed over heat enough to boil the gravy and cook the flour. Pour over the onions and serve. This is a delicious dish which puzzles meat-eaters, as they think they are eating a rich meat sauce.