1 Tbsp. margarine
1/2 onion, chopped
5 Tbsp. flour or cornstarch
salt and pepper (to taste)
5 Tbsp. dry milk
2 cups water
1–2 cups leftover beef
1 tsp. beef bouillon powder
1 small can mushroom pieces
Reduce the heat. Simmer, stirring constantly, until heated through. Serve over noodles, rice or mashed potatoes or toast. Serves 4.
Find it online: https://www.livingonadime.com/steak-mushroom-gravy/