Prepare the cabbage: Bring a large pot of water to a boil. Carefully separate the cabbage leaves and blanch them for 2–3 minutes until soft and flexible. Set aside to cool, then trim the thick center veins for easier rolling.
Make the filling: In a large bowl, combine ground beef, ground pork, cooked rice, onion, garlic, and egg. Season with salt, pepper, and paprika. Mix thoroughly until well combined.
Assemble the rolls: Place 2–3 tablespoons of filling onto each cabbage leaf. Fold in the sides and roll tightly to secure. Repeat with remaining leaves and filling.
Prepare the sauce: In a bowl, mix tomato sauce, beef broth, lemon juice, and brown sugar until well combined.
Cook the rolls: Spread a layer of sauce on the bottom of a large pot or Dutch oven. Arrange cabbage rolls in layers, then pour the remaining sauce over them.
Simmer: Cover and cook on low heat for 1 to 1½ hours, until the cabbage is tender and the meat is fully cooked. Let rest for a few minutes before serving.
