1. Bring a large pot of water to a boil. Add the head of cabbage and bring back to a boil. Boil the cabbage for 5 minutes, then drain and let cool. When cool enough to handle, trim the cabbage, removing about 1/2 inch of the stem. Carefully remove 18 large leaves and set aside. Set the remaining leaves aside.
2. Combine the ground meats, rice, grated onions, eggs, 1 teaspoon of salt, and 1/4 teaspoon of pepper in a large bowl. Mix to blend thoroughly.
3. Place a cabbage leaf on your work surface and use a knife to cut the end of the rib out in a v-shape. This will make it easier to roll the leaf. Add approximately 1/3 cup of the meat mixture to the center of the cabbage leaf and roll up, burrito style, tucking the ends in as you roll. Repeat with the remaining leaves and meat mixture.
4. Arrange the cabbage rolls, seam sides down, in a Dutch oven or large casserole.
5. Heat the oven to 350 F.

Make the Sauce

1. In a large saucepan, sauté the chopped onion until translucent. Add the tomato sauce, diced tomatoes, lemon juice or vinegar, and brown sugar. Taste and season with salt and pepper.
2. Pour the sauce mixture over the cabbage rolls in the Dutch oven or casserole. Cover the pan or casserole tightly and bake for 1 1/2 hours. Uncover and continue baking for 20 to 30 minutes.
3. Arrange the cabbage rolls in a serving dish and serve. Enjoy!