Defrost the cabbage the night before cooking. When it is completely defrosted, separate the leaves.
To make the filling: In a large bowl, mix the ground beef, salt, pepper, eggs, rice, ketchup, and chopped onion; set aside.
Place 1 heaping tablespoon of the filling on each cabbage leaf. Tuck the ends in and roll up like a big cigar. Place them, open side down, in a 6-quart casserole.
To make the sauce: Cook onions with oil in a saucepan for a few minutes, then add the tomatoes, tomato paste, salt and pepper to taste, onions, ketchup, the juice of one lemon, brown sugar, and raisins. Bring to a boil and let simmer for 15 minutes, covered.
Pour the sauce over the cabbage. Cover with foil and bake at 350 degrees for one hour and a half, and then uncover for an additional half hour, adding water if too dry. Taste for sweet and sour and, if needed, squeeze the juice of the remaining lemon over all.
Turn the stuffed cabbage rolls onto a serving platter, spoon the sauce over, and serve. This is even more delicious the second day.