Peel and quarter potatoes, place in COLD salted water.
Add potatoes (and garlic if using) and cook uncovered 15 minutes or until fork tender. Drain well.
Heat milk on the stove top (or in the microwave) until warm.
Add butter to the potatoes and begin mashing. Pour in milk a little at a time while using a potato masher to reach desired consistency.
Season with salt and pepper. Serve hot.