Prepping the Cabbage Leaves:
In a large pot, cook cabbage in boiling water for 9 minutes or until outer leaves are tender; drain. Rinse in cold water; drain. Remove 10 large outer leaves (refrigerate remaining cabbage for another use); set aside.
Making the Sauce:
In a large saucepan, saute 1 cup of the onion in butter until tender. Add the tomatoes, garlic, brown sugar and 1/2 teaspoon salt. Simmer for 15 minutes, stirring occasionally.
Making the Filling:
Meanwhile, in a large bowl, combine the rice, ketchup, Worcestershire sauce, pepper and remaining 1/2 cup onion and salt. Crumble beef and sausage over mixture and hand-mix until homogenized.
Making the Rolls:
Remove thick vein from cabbage leaves (about 3" up) for easier rolling. Place about 1/3-1/2 cup meat mixture on each leaf; fold in sides. Starting at the bottom (thick) edge, roll up leaf to completely enclose filling. Secure in place with toothpicks and place seam side down in a skillet. Top with the sauce.
Cooking the Rolls:
Cover and cook over medium-low heat for 1 hour. Reduce heat to low; cook 20 minutes longer or until rolls are heated through and a thermometer inserted in the filling reads 160°. Yield: 5 servings (2 rolls per person).