Peel potatoes and boil whole until tender, approximately 45 minutes. Drain and mash.
Melt butter over very low heat in a medium saucepan. Add crushed garlic and continue cooking while stirring for 1 minute. Do not allow garlic to brown. Stir in milk. Add salt and pepper and graualy add grated cheese, stirring, constantly. Allow cheese to melt and pour over mashed potatoes. Beat potatoes to desired consistency.