Warm the olive oil in a large pot over medium heat.
Sauté the onion until translucent, 4–5 minutes. Stir in garlic for 30 seconds.
Add ground beef. Cook and crumble until browned. Drain excess fat if needed.
Season with paprika, oregano, salt, pepper, and red pepper flakes. Cook 1 minute to bloom spices.
Stir in the chopped cabbage and cook until slightly wilted, about 3 minutes.
Pour in crushed tomatoes, tomato sauce, beef broth, tomato paste, Worcestershire, sugar, and vinegar. Stir well.
Mix in rinsed rice and bring the pot to a gentle boil.
Reduce heat to low, cover, and simmer 20–25 minutes, stirring once or twice.
Rest 5 minutes off heat. Adjust seasoning. Sprinkle with parsley and serve warm.