Preheat grill for medium heat. Combine olive oil, balsamic, garlic, tomatoes, salt, pepper flakes, basil and parsley in a small bowl. Cut polenta into 12 equal slices. Brush with oil and place on grill rack. Cook on direct heat until one side is golden brown, about 3 minutes. Turn slices, place cheese on top and grill polenta for an additional 5-6 minutes. Remove polenta from heat and top with tomato-herb topping. Drizzle with a little extra olive oil and some balsamic before serving.