Preheat the broiler.

Cook pasta according to the package directions; drain.

Heat a large skillet over medium-high heat; add olive oil. Add the sirloin to the pan and cook until browned.

Add the onion and chili powder to the pan; season with salt and pepper. Cook until the onion is tender. Add the ketchup, mustard and beef stock, bring up to a bubble and simmer until slightly thickened.

Toss together the chili and the pasta. Transfer to a casserole dish and top with the shredded cheese. Place the casserole under the broiler to melt and brown the cheese.

Per Serving (excluding unknown items): 747 Calories; 35g Fat (42.9% calories from fat); 39g Protein; 66g Carbohydrate; 4g Dietary Fiber; 108g Cholesterol; 998g Sodium.