Steps
1. Heat the oil in a large skillet over medium heat.
2. Add the ketchup, onion, garlic, garam masala, and cumin.
Cook, stirring often, for 5 minutes.
3. Add the tomatoes and cook for an additional 3 minutes.
4. Add the potatoes and cook, stirring often, for 15 minutes, or until tender.
5. Pour in the milk and season with salt and pepper.
6. Stir in the cheese and cook until melted.
7. Serve the potato masala warm, topped with more cheese if desired.