Sauté Garlic: Begin by heating 1 tablespoon of avocado oil in a large skillet over medium heat. Once hot, add the 4 minced garlic cloves and sauté for about 1-2 minutes, or until the garlic becomes fragrant but not browned.
Brown Beef: Next, add the 1 1/2 lbs of ground beef into the skillet. Season with 1 1/2 teaspoons of sea salt and 1/2 teaspoon of black pepper. Cook until the beef is fully browned, typically around 6-8 minutes. Be sure to crumble the beef as it cooks for even browning.
Mix with Rice: Stir in 4 cups of cauliflower rice along with 2 tablespoons of Italian seasoning. Allow this mixture to cook for an additional 3-4 minutes, melding the flavors together and ensuring the cauliflower rice is tender.
Layer Casserole: Preheat your oven to 375°F (190°C). In a large baking dish, layer half of the beef mixture evenly across the bottom. Next, sprinkle with half of the 3 cups of chopped cabbage and pour over half of the 3 cups of marinara sauce. Repeat these layers once more, finishing with a layer of marinara sauce.
Add Cheese & Bake: Sprinkle 3 cups of shredded mozzarella cheese over the top. Cover the dish with foil and bake in the preheated oven for 30 minutes. After this time, carefully remove the foil and continue baking for an additional 10-15 minutes, or until the cheese is bubbly and golden brown.