Start by browning the ground beef in a large pot or Dutch oven over medium heat, along with half of the salt and pepper. Drain any excess fat for a healthier dish.
Push the browned beef to one side of the pot. Add the diced yellow onion and the remaining salt and pepper, cooking until the onions become soft and translucent.
Stir in the minced garlic for about 15 seconds, being careful not to let it brown.
Next, mix in the smoked paprika, tomato paste, dried parsley, and dried thyme. Stir for a minute to combine the flavors.
Pour in the chicken broth and tomato sauce, scraping up any delicious browned bits from the bottom of the pot. Stir in the cauliflower rice, then cover the pot and let it simmer on low for 5 minutes. While it simmers, preheat your oven to 375°F (190°C).
Add the chopped cabbage to the pot, stirring until it's well combined with the meaty tomato sauce.
Transfer this flavorful mixture into a 9x13 inch casserole baking dish that has been lightly sprayed with nonstick spray. Cover the dish tightly with aluminum foil.
Bake for 40 minutes.
Remove the casserole from the oven and increase the oven temperature to 425°F (220°C). Sprinkle the shredded mozzarella cheese evenly over the top.
Bake uncovered for another 10 minutes, or until the cheese is beautifully melted, golden, and bubbly.
Let the casserole cool slightly before slicing and serving this comforting, healthy meal.