Cook tortellini according to package directions. Drain. Meanwhile, place the beans and milk in a food processor bowl or blender container. Cover and process or blend until smooth.
Transfer to a large skillet. Stir in grated Parmesan cheese, red and/or yellow pepper, green pepper, oregano, salt, nutmeg, and pepper. Cook and stir until heated through. Serve sauce over drained tortellini. If desired, sprinkle with shredded Parmesan cheese and garnish with fresh oregano. Makes 4 servings.