Oven Baked Cabbage Rolls

12 cabbage leaves
1 pound ground beef
3/4 cup cooked rice
1/2 cup finely chopped onion
2 cloves garlic, minced
1 egg
2 teaspoons salt
1 teaspoon pepper
1/2 cup milk

Sauce:
1 cans (8 ounces ) tomato sauce
1 can (14.5 ounces) diced tomatoes, undrained
3 tablespoons sugar
2 tablespoons vinegar
1/2 cup water
2 tablespoons cornstarch mixed with 1/4 cup cold water

Drop cabbage leaves into boiling salted water; cover and cook for 3 minutes. Drain well. Combine ground beef, rice, onion, egg, and salt, pepper, and milk. Mix well and divide into 12 portions.
Place a portion into the center of each cabbage leaf. Roll leaf around filling; fasten with toothpick. Place in a baking dish.

For sauce, combine tomato sauce, tomatoes, sugar, vinegar, and 1/2 cup of water and pour over cabbage rolls. Bake covered in a preheated 350 degree oven 40 to 45 minutes. Remove rolls and discard toothpicks. Place pan with juices over medium heat and stir cornstarch and water mixture into the sauce; bring to a boil and cook and whisk until thickened. Pour thickened sauce over cabbage rolls or serve on the side.