In a large saucepan heat olive oil over medium-high heat. Cook and stir the mushrooms and onion in hot oil until onion is tender. Stir in the orzo. Cook and stir about 2 minutes more or until orzo is lightly browned. Remove from heat.
Carefully stir in the chicken broth, carrot, marjoram, and pepper. Bring to boiling; reduce heat. Simmer, covered, about 15 minutes or until orzo is tender but still firm. Remove saucepan from heat; stir in broccoli. Let stand, covered, for 5 minutes. Makes six 2/3-cup servings.