In large sauté pan, cook cauliflower rice in 1 Tablespoon fat for 8 minutes over medium heat to melt and reduce water content. Remove cauliflower rice to a plate or bowl; set aside.
Preheat the oven to 350 degrees F.
Add ground beef, remaining fat and sea salt to same sauté pan over medium-high heat. Cook, breaking up meat with a spatula, until most of the pink is gone, about 5 minutes. Add cauliflower rice, herbs and spices: oregano, cumin, optional chili powder, garlic and black pepper. Sauté an additional 2 to 3 minutes until fragrant. Remove from heat.
To same large sauté pan (or use large mixing bowl if sauté pan isn't big enough), add raw chopped cabbage, salsa and tomato paste. Stir well. (See Process Photos below in Recipe Notes.)
Pour into a 9"x13" glass baking dish. Spread out and smooth the top slightly.
Bake for 30 minutes.
Top with grated cheese. (Cheese optional: if not, continue baking without it.) Bake for about 15 minutes more, until the cheese is well melted and golden brown and the casserole is cooked through, bubbly on the sides, hot and tender in the middle.
Serve on its own or with optional condiments: sour cream, cilantro etc. For dairy-free, drizzle with dairy-free crema or serve with avocado/guacamole etc.