Prepare the cabbage: Remove any damaged outer leaves from the cabbage. Cut it into quarters, remove the firm core, and chop the leaves into roughly 1-inch pieces. Keep the pieces similar in size so they soften evenly.

Brown the ground beef: Place the ground beef in a 12-inch (30 cm) deep skillet over medium-high heat. Cook for 6 to 8 minutes, breaking it into small crumbles with a spatula. Continue until no pink remains and the beef reaches 160°F (71°C). Drain excess grease if more than a thin coating remains.

Soften the onion: Add the diced onion and 1/4 teaspoon of the salt to the skillet. Cook over medium heat for 3 to 4 minutes, stirring occasionally, until the onion looks translucent and begins to soften.

Cook the tomato paste and seasonings: Add the garlic, tomato paste, smoked paprika, oregano, black pepper, and remaining 1/2 teaspoon salt. Cook for 1 minute, stirring constantly. The tomato paste should darken slightly and coat the beef without burning.

Add the tomatoes and broth: Stir in the diced tomatoes with their juices, beef broth, and Worcestershire sauce. Scrape the bottom of the skillet to loosen any browned bits. Bring the mixture to a gentle simmer.

Add the cabbage in batches: Add about half of the chopped cabbage and fold it into the beef mixture. Once it begins to wilt, add the remaining cabbage. The skillet may look very full at first, but the cabbage will reduce substantially as it cooks.

Cover and cook: Reduce the heat to medium-low and cover the skillet. Cook for 10 minutes, stirring once halfway through. The cabbage should release moisture and become noticeably softer.

Finish uncovered: Remove the lid and increase the heat to medium. Cook for another 4 to 6 minutes, stirring occasionally, until the cabbage is tender but not mushy and most of the watery liquid has evaporated. If the skillet becomes dry before the cabbage is tender, add 2 tablespoons (30 ml) of broth or water.

Add the vinegar: Remove the skillet from the heat and stir in the apple cider vinegar. Taste and adjust the salt or pepper only if needed. The vinegar should brighten the tomato and cabbage flavors without making the dish taste sharply sour.

Rest and serve: Let the Ground Beef and Cabbage rest uncovered for 5 minutes. The juices should settle into a lightly saucy consistency. Sprinkle with chopped parsley, if using, and serve warm.