Trim off the roots of the onions, wipe, but do not skin. Put a little margarine, butter or dripping in a fireproof dish, or roasting-tin. Place the onions in it and bake until tender in a fairly hot oven (375° F., Gas 5). Take out the onions and peel them. Put them back in the dish, season with salt and pepper, and baste well, using a little extra fat if necessary. Reheat for 10 min.