Remove about 15 large leaves from the cabbage; cut off very thick part of each leaf. Pour boiling water over the cabbage to wilt the leaves.
Preheat oven to 350°.
Combine ground chuck with the rice, grated onion, eggs, 1 teaspoon salt, 1/4 teaspoon pepper. Place a mound of meat mixture in cupped part of each softened cabbage leaf. Fold over sides of cabbage leaf; roll up. In bottom of Dutch oven, place a few of the remaining leaves. Arrange layers of cabbage rolls, seam side down, and sliced onions in a Dutch oven or large casserole. Pour on tomato sauce, tomatoes, lemon juice, and 1 teaspoon salt and 1/4 teaspoon pepper. Bring to a boil on stove top. Sprinkle with brown sugar, to taste.
Bake, covered, for 1 hour. Uncover and bake 2 hours longer.
Calories per serving: 243