Brown beef with onion, chopped peppers, garlic, chili powder, cumin, oregano, salt and pepper in a large, nonstick skillet set over medium heat.

Stir in tomatoes, black beans and corn. Simmer, partially covered and stirring occasionally, for 20 minutes.

Meanwhile, cook macaroni according to package directions. Spoon chili over macaroni and garnish with sour cream and cheese (if using).