01 -
In a large bowl, mix the ground beef, French onion soup mix, breadcrumbs, milk, egg, and Parmesan cheese until well combined. Form the mixture into meatballs.
02 -
In a skillet over medium heat, heat the olive oil. Add the meatballs and brown them on all sides. Once browned, transfer the meatballs to the slow cooker.
03 -
In the same skillet, add the sliced onions. Cook until the onions are golden brown and caramelized, about 10-15 minutes. Add the caramelized onions on top of the meatballs in the slow cooker.
04 -
In a bowl, mix the beef broth and Worcestershire sauce. Pour the mixture over the meatballs and onions in the slow cooker.
05 -
Set the slow cooker on low for 6-8 hours or on high for 3-4 hours. Adjust seasoning with salt and pepper as needed.
06 -
Before serving, garnish with fresh thyme. Enjoy the meatballs hot!