1. Bring broth to a simmer in a medium saucepan; keep warm.
2. Heat oil in a large non-stick skillet over medium-high heat. Add zucchini and onion; sauté 5 minutes or until tender, stirring frequently. Add barley; cook 1 minute, stirring constantly.
3. Stir in 1 cup broth; cook 5 minutes or until liquid is nearly absorbed, stirring frequently. Stir in 1/2 cup broth and salt. Add remaining broth, 1/2 cup at a time, stirring frequently until each portion of broth is absorbed before adding the next (about 25 minutes). Add shrimp; cook 4 minutes. Stir in cheese, butter, and pepper.