Bring a large pot of salted water to a boil. Add potatoes and garlic, lower heat to medium, and simmer until potatoes are tender, 15 to 20 minutes.

When the potatoes are almost finished, heat milk and butter in a small saucepan over low heat until butter is melted.

Drain potatoes and return to the pot. Slowly add warm milk mixture, blending it in with a potato masher or electric mixer until potatoes are smooth and creamy. Season with salt and pepper.