Heat oil in a large Dutch oven over medium-high heat. Add zucchini and garlic, and sauté 30 seconds. Stir in black pepper, tomatoes, and chickpeas; reduce heat, and simmer 10 minutes, stirring occasionally.
While stew cooks, bring 3 cups water to a boil in a medium saucepan. Add polenta, stirring with a whisk. Reduce heat; simmer 3 minutes or until done, stirring occasionally. Stir in cheese. Serve stew over polenta.