Ovenless Baked Beans

2 cups cooked and drained navy beans
2 tablespoons brown sugar
1/2 cup tomato sauce
1/2 cup liquid from beans
1 medium onion, cut in rings
1 1/2 teaspoons salt
1 teaspoon vetsin
1 tablespoon margarine

Saute onion ring in hot margarine; save some onion rings for garnish. Add the tomato sauce to the sauteed onion rings. Add the water, salt, sugar and vetsin, and let simmer. Add the cooked beans, let simmer over low fire until half of the liquid has evaporated. Garnish with onion rings. Makes 5 servings.