In a large skillet over medium heat, add the ground beef, diced onion, garlic, oregano, and chili flakes. Cook for 7–8 minutes, breaking up the beef with a spatula, until browned and the onions are soft.
Stir in the shredded cabbage and diced tomatoes (with their juices). Reduce heat to medium-low, cover, and let simmer for 25–30 minutes, stirring occasionally, until the cabbage is tender and the flavors are well combined.
Garnish with fresh parsley if desired. Serve hot as a main dish on its own or with rice or potatoes.
Slice cabbage evenly: Thin, uniform shreds cook down faster and more evenly.
Simmer covered: Keeping the skillet covered helps the cabbage soften and allows the flavors to meld.
Stir occasionally: This prevents sticking and ensures the cabbage cooks evenly throughout.
Customize the flavor: Add a splash of Worcestershire sauce or a teaspoon of smoked paprika for extra depth.
Use what you have: Ground turkey or chicken can be swapped for beef, and chopped bell pepper or carrots can be added with the onions for extra veggies.
Leftovers reheat well: This dish is even more flavorful the next day, perfect for make-ahead meals.