In a 12 inch frying pan or 2 to 3 quart pan, combine onion, mushrooms, garlic, and 1/2 cup water. Cook, uncovered, on high heat until liquid evaporates and a brown film forms in pan, about 15 minutes; stir often. Add 2 or 3 tablespoons water and stir to free the brown film; cook until the film forms again. Repeat this step 4 or 5 times until onions are richly browned, about 15 minutes.
Rinse and drain rice. Mix with broth in pan. Bring to a boil on high heat; cover, and simmer 30 minutes. Rinse and drain barley. Add to rice; simmer until grains are tender to bite but just slightly chewy, about 20 minutes longer.
Season with salt and pepper to taste. Makes 5 or 6 servings.
Per serving: 184 cal. (7.3 percent from fat); 7.8 g protein; 1.5 g fat (0.7 g sat.); 217 g carbo.; 36 mg sodium; 0 mg chol.