3 Idaho potatoes
1 cup of shredded sharp cheddar cheese
¾ cup of heavy cream
½ cup of milk
2 tablespoons of flour
3 tablespoons of butter
salt and pepper

Peel and gently simmer the potatoes in boiling salted water for 30-40 minutes until cooked through. Plunk in ice water for 10 minutes to chill.

Meanwhile, heat the butter in a small sauce pan on medium high. Once foaming, add the flour and whisk together. Then lower the heat to low and add the cream and milk. Keep on the low heat, continuing to stir until thickened. Then, in 2 batches, add the shredded cheese (reserving 3 tablespoons of the cheese), whisking constantly until it is all incorporated. Turn off the heat then add your salt and pepper.

Preheat your broiler.

Cut the potatoes into ¼ inch slices and put the slices in a 9 inch oval baking dish. Pour on the cheese sauce and gently mix. Sprinkle the top with the reserved shredded cheese.

Put the gratin under the broiler for 5 minutes until the top is brown and crispy.

Serves 4.