Peel potatoes, rinse and cut into 1-inch pieces. Place potatoes in a large pot and cover completely with water. Bring to a boil over medium-high heat and let boil for 20 minutes or until tender.
Drain potatoes and place in a large mixing bowl. Add garlic and mash with a potato masher.
Add yogurt, milk, butter, parmesan cheese and season with salt and pepper, to taste. Mix until well combined and you reach desired consistency.