Pull off a couple of the rough outer leaves. Using a small paring knife at a 45-degree angle, cut around the core and remove it from the head.

Place the whole head in a large pot and cover with about 12 cups of water. Bring to a boil, then reduce to medium and cook 3 to 5 minutes, until the leaves turn bright green. Turn the head once or twice if it isn't fully submerged. Set on a cutting board to cool.

Zest one lemon to get 1 teaspoon of zest, avoiding the bitter white pith.

In a large bowl, combine the ground beef, ground pork, cooked rice, lemon zest, grated onion, grated garlic, and egg. Mix together with clean hands until well combined. Cover and refrigerate until ready to assemble.

Heat the olive oil in a pot over medium heat. Add the grated onion and cook about 2 minutes. Add the garlic and cook another 2 minutes.

Stir in the crushed tomatoes, water, salt, and pepper. Bring to a bubble, then reduce the heat and simmer about 15 minutes.

Once the cabbage is cool enough to handle, peel off a leaf and trim the hard rib at the base by cutting out a small triangle, leaving the leaf intact.

Place about 2 tablespoons of filling near the trimmed end. Roll up partway, fold in the sides, and finish rolling.

Grease a 9x13 baking dish and spread about 3/4 cup of sauce over the bottom. Arrange the rolls in rows, seam side down. Pour the remaining sauce over the top.

Move the oven rack to the upper-middle position. Bake at 350°F for 60 minutes. If not using a convection oven, turn the rolls at the 30-minute mark for even cooking.

Garnish with fresh parsley if desired. Let rest about 15 minutes before serving.