Preheat oven to 400°. Lightly coat an 8- x 10-inch baking dish with olive oil. Slice polenta into 1/2-inch-thick slices; arrange slices in a single layer in baking dish. Heat a 2-quart saucepan over medium heat; add 1 tablespoon olive oil and crushed garlic clove to pan. Cook until the garlic is soft (2-3 minutes). Add crushed tomatoes, dried oregano, salt, and 1/4 cup chopped fresh basil to pan; bring to a boil. Reduce heat, and cook until thick (about 10 minutes). Spoon tomato sauce over polenta; sprinkle with fresh mozzarella and Parmigiano-Reggiano. Bake until bubbly and golden (20-25 minutes). Garnish with chopped basil; serve.