Preheat oven to 375°F (190°C). Grease a baking dish.
Cook beef & onion: In a skillet, melt butter and sauté onion until soft. Add ground beef, garlic, salt, pepper, and paprika. Cook until browned. Drain excess grease.
Prepare sauce: In a bowl, whisk heavy cream, cream cheese, and beef broth until smooth.
Assemble casserole: Layer turnip slices in the baking dish, spread cooked beef over them, pour the creamy sauce, and top with shredded cheese.
Bake for 25-30 minutes until bubbly and golden.
Serve & enjoy! Perfect with a side salad or keto bread.