1. Cook penne according to package directions. Two to three minutes before penne is ready, add broccoli to penne. Finish cooking and drain.
2. While pasta cooks, heat oil in a large skillet over medium-high heat. Saute the garlic until aromatic (1-2 minutes).
3. Add broth and boil until reduced by half (3-5 minutes). Stir in pasta, broccoli, and lemon zest and cook until coated with sauce (2-3 minutes). Season with pepper and serve warm, topped with cheese.