Melt butter, add onions, cloves & garlic, and cook 6 min. Add flour, cook until pale brown. Add ground chuck & bell peppers and cook 10 min. Add tomatoes, tomato sauce, mushrooms and bacon pieces and cook 5 min. Add seasonings of salt, pepper, paprika & Worcestershire sauce. Pour sauce over cooked spaghetti and mix well.
Pour into baking dish or pan. Let stand in refrigerator for 24 hours (to marinate flavors).
Bake in oven 1 hour at 350 degrees F. Sprinkle KRAFT Sharp Cheddar Cheese and spread over top in last 10 min before oven time expires.