In a large bowl, combine ground beef, breadcrumbs, Parmesan cheese, milk, eggs, Worcestershire sauce, salt, and pepper. Mix until just combined.
Shape the mixture into a loaf and place it in the crockpot.
In a skillet, melt butter over medium heat. Add the thinly sliced onions and cook until caramelized, about 15 minutes.
Pour the caramelized onions and beef broth over the meatloaf in the crockpot.
Cover and cook on low for 6-7 hours or until the meatloaf is fully cooked and tender.
About 15 minutes before serving, top the meatloaf with Swiss cheese slices, cover, and allow the cheese to melt.
Slice and serve the meatloaf with the onions and broth spooned over the top.
Prep Time: 20 minutes | Cooking Time: 7 hours | Total Time: 7 hours 20 minutes
Kcal: 470 kcal | Servings: 6 servings
