Heat oil in large heavy pot over medium high heat. In a pie plate combine salt, pepper and flour with a fork. Toss sirloin cubes with flour to coat. Shake off excess flour. Brown sirloin in pot on all sides and remove meat to a plate. If necessary add more oil to pan and add onions. Cook onions over medium heat until they begin to soften. Stir in green, red and jalapeno peppers and cook for 3 to 5 minutes. Add chili powder, cumin and oregano. Return browned meat to pan and pour in beer and beef stock. Bring to a boil and cover and reduce heat to a simmer. Cook for 45 minutes or until meat is tender. Add crushed tomatoes and cook for 20 minutes. Stir in black and kidney beans and gently simmer for 10 minutes. Serve with cheddar, onion, scallions and sour cream.