Preheat oven to 425ºF. Bring a large stock pot with salted water to a boil. Add a head of cabbage to the pot and cook for 2 minutes. Use a large fork to partially lift the cabbage from the water, then with a paring knife, remove the softened outer leaves. Place the cabbage back in the pot and repeat until all leaves are removed.
Preheat a large skillet on medium-high heat and add the olive oil. Add the onion and garlic, and cook until translucent, stirring occasionally. Add the Italian seasoning and cook for another 30 seconds, stirring a few times. Transfer the onions and garlic to a large bowl.
To the same bowl, add the ground beef, ground pork, uncooked rice, salt, and 1 teaspoon of black pepper and mix well using your hands.
Remove the thick stem on the cabbage leaves. Lay the cabbage leaf flat, add 1/4 cup - 1/3 cup of the filling in the center, tuck in the sides and roll the cabbage up. Place the cabbage rolls with the seam side down in a large Dutch oven. Repeat with remaining ingredients, overlapping two smaller leaves if needed to hold the filling.
In a large bowl combine the tomato sauce, chicken broth, and remaining 1 teaspoon pepper. Stir the ingredients together, pour the mixture over the cabbage rolls and cover with a lid.
Bake cabbage rolls for 90 minutes. Remove from the oven, let stand for 15 minutes and serve hot with sour cream and dill (optional).