French Onion Crock Pot Meatloaf 1. Slice onion and carmelize with 2 tbs butter and a splash of Worcestershire sauce. 2. Prepare Meatloaf. Combine 1.5 pounds ground beef (I used 93/7 lbs to avoid too much grease), 1 cup breadcrumbs, 1 envelope French onion soup mix and garlic, salt, pepper and Worcestershire to taste. 3. Lay meatloaf over bed of carmelized onions and cook on low for 3 hours. 4. Add sliced Swiss cheese and cover to melt before serving.