Bring a large pot of salted water to a boil over high heat. Gently add the potatoes and the garlic, and lower the heat to a simmer. Cook, partially covered, until tender, 20-25 minutes. Drain the potatoes and return them to the pot over high heat. Toss potatoes for 2 minutes, until the moisture evaporates.
In a small pot over medium heat, heat the milk with the butter until the butter has melted.
Use a potato ricer to press the potatoes into a large mixing bowl. Drizzle in the milk and butter mixture, and stir to combine. Season to taste with salt and pepper.