In a medium saucepan, cook mushrooms, onion, and garlic in hot butter or margarine until tender.
Carefully add water, bouillon granules, and pepper; bring to boiling. Stir in zucchini, carrot, and rices. Return mixture to boiling; reduce heat.
Simmer, covered, about 40 minutes or until the rices are tender and most of the liquid is absorbed. Stir in nuts. Makes 6 side-dish servings.
To toast nuts, place in a small skillet and cook over medium heat for 5 to 7 minutes or until golden, stirring often. Or, spread in a shallow baking pan and bake in a 350 degree F oven for 5 to 10 minutes, stirring once or twice.