Place the potatoes, garlic and 1 teaspoon salt inside a large pot and cover them with cold water. Bring to a boil, then reduce the temperature to medium and cook covered until the potatoes are fork tender, 20-25 minutes.

Drain the potatoes and garlic in a colander and return them to the pot. Add the Greek yogurt, butter, remaining ¼ teaspoon salt and pepper while the potatoes are still hot and use a fork, masher or electric beaters to mash the potatoes.

Gradually add the milk while you continue to mash until you reach your desired consistency. Taste and season with more salt and pepper, if needed.

Serve warm and top with more butter and black pepper, if desired.