Coat a medium skillet with cooking spray. Place over medium-high heat until hot. Add turkey and garlic, and cook over medium heat until turkey is browned, stirring until turkey crumbles. Stir in tomatoes, Italian seasoning, and pepper. Bring to a boil; cover, reduce heat, and simmer 10 minutes. Set aside.
Slice polenta into 12 rounds. Place on a baking sheet coated with cooking spray. Broil 10 minutes on each side or until lightly browned. To serve, top polenta with turkey mixture; sprinkle with cheese.
Tip: Polenta is a cornmeal product similar to yellow grits. Precooked polenta comes in a package that looks like a tube of sausage and is usually found in the produce section of the grocery store.