How to Make It
Place the potatoes and garlic in a large pot and add enough water to cover. Bring to a boil and cook until tender, about 20 minutes. Drain the potatoes and garlic and return to the pot.
Add the sour cream, milk, and butter and mash with a potato masher. Add scallions and stir gently to combine well. Season to taste with salt and pepper. Serve hot.