Fresh Tomato Sauce (see separate recipe) ----------------------------------GARNISH---------------------------------Fresh Italian Parsley -chopped Herb sprigs Heat olive oil in a medium skillet; saute onion, garlic, and sweet pepper until hot through. Add crumbled sausage and continue cooking just until meat changes color. Stir in mushrooms and cook until hot through. Drain excess fat and set mixture aside. Place milk or other liquid in a large, heavy saucepan over moderately high heat; slowly add cornmeal, stirring briskly with a wire whisk to prevent lumping. Bring to a boil and cook 10 minutes, or until mixture is very thick and smooth; stir constantly to prevent scorching. Remove pan from heat and stir in herbs, cayenne pepper, and ricotta and gruyere cheeses. Add sausage and sweet pepper mixture, combine well, then season to taste with salt and pepper. Pour mixture into two 9-inch pie plates lined with plastic wrap. Cool on a wire rack, then cover and refrigerate at least an hour, or as long as three days. When ready to serve dish, preheat oven to 375 degrees F. Cut polenta in wedges and place on an oiled shallow baking pan large enough to hold polenta in one layer without crowding. Drizzle with melted butter and sprinkle with parmesan cheese. Bake 15 to 20 minutes, or until polenta is lightly browned and very hot when tested with a small knife in center of wedge. Serve with Fresh Tomato Sauce, and garnish with chopped fresh parsley and sprigs of herbs.