Heat olive oil in a large pot over medium high heat. Add onions, green peppers, mushrooms and minced garlic. Sautee about 5 minutes, or until vegetables are tender.
Add ground beef and cook until browned, crumbling with your spoon or spatula as it cooks. Drain beef mixture in a colander and return to pot.
Add cayenne pepper, crushed red pepper, oregano and chili powder, salt and pepper. Stir well to combine.
Add diced tomatoes, kidney beans, tomato sauce, beer and brown sugar. Bring just to boiling, reduce heat and simmer (covered) for 1 hour.
Recipe courtesy of: The Blond Cook