Saute the onion in the butter in a small skillet over medium-high heat, stirring frequently, until the onions are golden brown, about 8-10 minutes.

Peel the potato and carrot. Cut the potato into eight pieces, and the carrot into six pieces. Cook in boiling water until tender, about 8-10 minutes. Drain well.

Mash the potato and carrot together until the carrot is in small chunks. Beat in the sauteed onion, ricotta cheese and salt. Cover and keep warm. (This dish can be reheated in a microwave oven or in a double boiler over low heat.)

Per serving with non-fat ricotta cheese: 182 calories, 7 grams protein, 35 grams cabohydrates, 3.4 grams fiber, 0.2 grams fat (0 grams saturated), 299 milligrams sodium.

With part-skim ricotta cheese: 184 calories, 6.5 grams protein, 34.6 grams carbohydrates, 3.5 grams fiber, 2.6 grams fat (1.5 grams saturated), 322 milligrams sodium.