1. Preheat your Air Fryer to 400 F (200 C). Grease baking dish with cooking oil spray.
2. Heat oil in large pan or skillet over medium-high heat. Add beef and cook 5-7 minutes on each side or until browned on all sides. Reserve juice in the pan.
3. Place beef on a greased baking dish that can fit into the Air Fryer. Season beef with salt and pepper.
4. Cook for 15-20 minutes or to your desired doneness. Cool for 10 minutes before slicing.
5. Meanwhile, melt butter in the reserved pan over medium heat. Stir-fry onion and garlic for 3 minutes.
6. Stir in wine and increase heat to high. Add the cranberries, beef stock, thyme, and chili flakes. Cook 10 to 15 minutes or until sauce becomes thickened. Season with salt and pepper, to taste.
7. Serve roast beef topped with spicy cranberry sauce.