Garlic Ranch Mashed Potatoes

Bahan-bahan (8 porsi)

• 4 pounds red potatoes
• 4 cloves garlic
• 4 tablespoons salted butter
• 1 cup sour cream (or greek yogurt)
• ⅔ cup ranch dressing (store bought or homemade)
• salt and black pepper (to taste)
• milk (or cream as needed)