01 - Preheat your oven to 375°F.
02 - Heat olive oil in a large skillet over medium heat. Sauté onion and red bell pepper for 3-4 minutes until softened.
03 - Add minced garlic and cook for 1 minute, stirring frequently to prevent burning.
04 - Add ground beef to the skillet, breaking it apart with a spatula. Cook until browned, about 5-7 minutes. Drain excess fat if needed.
05 - Stir in oregano, basil, smoked paprika, salt, black pepper, and red pepper flakes. Mix well to distribute spices evenly.
06 - Add cauliflower rice and baby spinach (if using). Cook for 4-5 minutes until cauliflower is tender and any liquid has evaporated.
07 - Remove skillet from heat. Stir in sour cream and half of the cheddar cheese until well combined and creamy.
08 - Spread the mixture evenly into a greased 9x13-inch baking dish.
09 - Sprinkle remaining cheddar cheese and all mozzarella cheese over the top in an even layer.
10 - Bake for 20 minutes, or until cheese is bubbly and golden brown.
11 - Let rest for 5 minutes before serving. Garnish with fresh parsley and serve warm.