Instructions:
- Slice off the tops (the lids) of the peppers. Carefully remove the seeds and membranes. Set the lids aside.
- Heat olive oil in a skillet over medium-high heat. Add the ground beef and onion; cook, breaking up the meat, until the beef is fully browned and the onion is translucent (about 6-8 minutes). Drain off any excess fat.
- Transfer the browned meat mixture to a large mixing bowl. Add the minced garlic, uncooked rice, beaten egg, tomato paste, smoked paprika, oregano, salt, pepper, and the ¼ cup of water. Mix thoroughly until everything is evenly distributed.
- In the slow cooker insert, combine the diced tomatoes (undrained), tomato sauce, broth, Italian seasoning, salt, and pepper. Stir well to create the cooking liquid.
- Carefully spoon the filling mixture into the hollowed-out peppers, packing them loosely but firmly.
- Place the stuffed peppers upright into the slow cooker insert, nestled into the tomato liquid. Place the reserved pepper lids gently on top of the stuffed peppers.
- Cover the slow cooker. Cook on LOW for 7–8 hours or HIGH for 4–5 hours. The peppers are done when they are very tender when poked with a fork.
- Allow the peppers to rest in the cooker (unplugged) for 10 minutes before serving directly from the slow cooker, spooning the rich sauce over the top.