Scrub potatoes. Bake in preheated oven ... medium heat; saute mushrooms 2 minutes then add scallions ... slice from each potato. Scoop out pulp. Add ... or until heated through.
Lightly brown onions and mushrooms in butter. Wash potatoes, slice thinly. In 1 1/2 quart casserole, arrange potato slices, sprinkle salt, pour spoonfuls of slightly thinned mushroom soup.