Add enough water (about 1/4 cup) to broth to make 2 cups. In a saucepan bring broth to boiling. Add rice. Return to boiling; reduce heat. Cover; simmer about 15 minutes or until tender. Cool to room temperature.
Meanwhile, in covered large saucepan cook asparagus in a small amount of boiling water for 2 minutes. Add peas; cook 2 to 3 minutes more or until crisp-tender. Drain. In large bowl combine cooled rice, asparagus and peas, nuts, cilantro or parsley, and green onions.
In a small bowl combine oil, lemon peel, lemon juice, sour cream or yogurt, salt, and white pepper. Pour over rice mixture; toss to coat. Cover; chill in the refrigerator at least 3 hours. To serve, line a large platter with spinach leaves. Top with torn spinach, then rice mixture. Garnish with lemon slices, if desired. Makes 6 side-dish servings.