Preheat oven to 375°F (190°C) and grease a 9×13″ casserole dish.,In a large skillet, cook ground beef over medium heat until browned. Drain fat, then add onion and garlic; cook until softened.,Bring a pot of salted water to boil. Add chopped cabbage and blanch 5–6 minutes until just tender; drain thoroughly.,In a saucepan, melt butter over medium heat, whisk in flour to form a roux and cook ~1 min.,Slowly whisk in milk and broth, cook until sauce thickens (~3–4 min). Stir in half the cheddar, salt, pepper, and spices.,Combine blanched cabbage and beef mixture into the sauce. Stir in rice or noodles and sour cream if using.,Transfer mixture to prepared casserole dish. Sprinkle remaining cheddar on top.,Bake uncovered 20–25 minutes until bubbly and cheese is golden.,Let rest 5–10 minutes before serving.