1. Preheat oven to 400 degrees F. 

2. Halve the garlic and rub the inside of a medium casserole dish. 

3. Wash and peel the potatoes and slice very thinly, preferably with a mandolin.

4. Add salt and pepper to milk and stir. 

5. Place a layer of potatoes, then cheese, and pour a portion of the milk mixture on top. Repeat until all the potatoes are used.

6. Bake for 30 minutes, then lower the heat to 300 degrees F and bake for another 1 1/2 hours. If potatoes start to dry out, place a sheet of aluminum foil over the casserole dish.