I found this recipe at allrecipes.com. I don't like Manwich, I think it's the green peppers in it, and this recipe did not call for them. I've been using this recipe for over two years now.
2 pounds ground beef
1/2 cup chopped onion
1 cup chopped celery (I don't use a full cup, usually 1 stalk)
1 (10.75 oz.) can condensed tomato soup
1/4 cup ketchup
1 T. white vinegar
1/4 cup packed brown sugar
1 1/2 tsp. Worcestershire sauce
1/2 tsp. salt
1/4 tsp. garlic powder
8 hamburger buns
Place ground beef in a large skillet over medium heat. Cook until evenly browned, stirring to crumble. Add onion and celery, cover the pan, and cook until tender and transparent, about 5 minutes. Drain off any grease.
Stir the tomato soup (undiluted), ketchup, vinegar, brown sugar and Worcestershire sauce into the beef mixture. Season with salt and garlic powder. Heat to a simmer over low heat, and cook until thoroughly heated, stirring frequently to prevent it from burning on the bottom.
Spoon the hot beef mixture onto buns, which may be toasted first, and serve.