In a large mixing bowl, mix together ground beef, green pepper, onion, eggs, salt, bread crumbs, 3/4 cups of whole milk & 3/4 cups of the ketchup
Use a spoon or your hands to thoroughly combine the ingredients.
Line your slow cooker with parchment paper. (Optional but recommended for easy cleanup)
Shape the meat mixture into a loaf and place in slow cooker.
Mix together the remaining ketchup with the mustard and spread over the top.
Cook on LOW for 6-8 hours.
ENJOY!