In a pot of salted boiling water, cook the cabbage leave for about 2 minutes. Drain on paper towels and allow to cool.
Heat oil in a large skillet and cook onions until tender. Stir in green pepper and garlic and cook for three minutes. Stir in crumbled ground round and cook until meat is browned. Add thyme and season to taste. Stir in 1 cup crushed tomatoes and simmer gently for 2 minutes. Stir in cooked white rice and toss to coat. In a small bowl, mix together 1 cup crushed tomatoes and chicken stock and spread out in bottom of baking dish.
Preheat oven to 350 degrees. Lay each cabbage leaf out flat ad place about 3/4 cup of rice mixture in center of leaf. Fold in sides of leaf and roll up. Place seam side down in baking dish. Cover dish with foil and bake for 20-30 minutes. Serve each cabbage roll up with a little sauce and garnish with chopped parsley