1. In a large pot, bring 4 cups of water to a boil.
2. Add potatoes and cook for 5 minutes.
3. Add cauliflower and cook for 5 more minutes, until the potatoes and cauliflower is soft. Drain.
4. In a large mixing bowl, add potatoes, cauliflower, and grated cheese. Mash with a fork until well blended.
5. Add milk, salt, pepper and garlic powder. Mix well.
6. Serve and enjoy!