Preheat your oven to 350°F (175°C).
In a large skillet, heat the olive oil over medium heat. Add the diced onion and sauté for about 3-4 minutes until softened. Stir in the minced garlic and cook for another minute until fragrant.
Add the ground beef (or turkey) to the skillet. Season with salt, black pepper, paprika, thyme, and crushed red pepper flakes if using. Cook until the meat is browned and cooked through, breaking it up with a spoon as it cooks.
Stir in the chopped cabbage and cook for about 5 minutes until it begins to wilt.
In a large mixing bowl, combine the diced tomatoes (with juice), uncooked rice, beef broth, and Worcestershire sauce. Mix well.
Add the meat and cabbage mixture to the bowl and stir until everything is well combined.
Transfer the mixture to a greased 9x13-inch baking dish. Cover with aluminum foil and bake for 45 minutes.
Remove the foil, sprinkle the shredded cheddar cheese on top, and bake uncovered for an additional 15 minutes until the cheese is melted and bubbly.
Let the casserole cool for about 5-10 minutes before serving.