Preheat the oven to 350?F.
Heat the olive oil in a large skillet over high heat. Add the sausage and cook until browned, breaking up clumps with a wooden spoon, about 5 minutes. Transfer the sausage to a paper towel-lined plate. Add the onions and bell peppers to the pan and cook until they begin to soften, about 2 minutes. Add the garlic and Italian Essence and cook for another 2 minutes. Return the sausage to the pan, stir to mix, and cook for another minute. Add the tomatoes and stir to mix. Cook until most of liquid has evaporated, about 7 minutes. Season with the black pepper and salt. Pour the sausage mixture into a 9 x 13-inch baking dish, distributing it evenly. Pour the polenta on top, spreading it evenly with a rubber spatula. Top the polenta with the butter and Parmesan. Bake until golden brown and bubbly, about 30 minutes.
Makes 8 to 10 servings