Sauté beef and 2 cups chopped onions in large Dutch oven over high heat until beef is cooked through, stirring often and breaking up beef with back of spoon, about 10 minutes.
Add cumin, chili powder, garlic powder and chipotle chilis; sauté 3 minutes. Mix in 2 1/2 cups water and 1/2 cup cilantro. Reduce heat to medium-low. Cover partially and cook 1 1/2 hours, adding more water by 1/4 cupfuls if chili becomes dry. Season with salt and pepper. (Can be made 1 day ahead. Cover; chill. Bring to simmer before continuing.)
Mix remaining 1/2 cup cilantro into chili. Ladle chili into bowls. Serve, passing cheese, sour cream and additional chopped onion separately.
*Canned chipotle chilis are available at Latin American markets, specialty foods stores and some supermarkets.
Servings: 4