Brown the beef: Heat a large pot over medium-high. Add ground beef and cook, breaking it up, until browned and no longer pink.
If there’s a lot of fat, spoon off some, leaving about 1 tablespoon for flavor.
Sauté aromatics: If using onion, add it to the pot with a splash of oil if needed. Cook 3–4 minutes until softened. Stir in garlic and cook 30 seconds until fragrant.
Toast the spices: Add tomato paste, smoked paprika, cumin, and thyme.
Stir and cook 1 minute to toast the paste and spices. This step deepens the flavor.
Add cabbage and carrot: Stir in sliced cabbage (and carrot, if using). Cook 2–3 minutes to let it wilt slightly.
Pour in broth: Add beef broth and bring to a gentle boil.
Reduce heat to a simmer.
Simmer: Cook uncovered for 20–25 minutes until the cabbage is tender and the flavors meld. Skim any excess fat if you prefer a lighter broth.
Finish and season: Stir in apple cider vinegar or lemon juice. Taste and season with salt, pepper, and red pepper flakes to your liking.
Serve: Ladle into bowls and top with fresh parsley or dill.
Enjoy hot.