Au Gratin Potatoes

Instructions

1. 1

   Preheat your oven to 375°F (190°C). Rub the inside of a 9x13 inch baking dish with the cut side of one garlic clove, then butter the dish generously.

2. 2

   Peel and slice the potatoes into 1/8-inch thick rounds using a mandoline or sharp knife for uniform thickness. Place sliced potatoes in cold water to prevent browning.

3. 3

   In a large saucepan over medium heat, melt the butter. Mince the remaining garlic and sauté for 1 minute until fragrant but not browned.

4. 4

   Whisk in the flour and cook for 1-2 minutes to create a roux, stirring constantly to avoid lumps.

5. 5

   Gradually pour in the heavy cream and milk while whisking continuously. Add thyme, salt, pepper, and nutmeg. Bring to a gentle simmer.

6. 6

   Reduce heat to low and stir in half of the gruyere and all of the cheddar cheese. Stir until completely melted and smooth. Remove from heat.

7. 7

   Drain the potato slices and pat them dry with a kitchen towel. Layer one-third of the potatoes in the prepared baking dish, slightly overlapping.

8. 8

   Pour one-third of the cheese sauce over the first layer of potatoes, spreading evenly. Repeat layering twice more, ending with sauce on top.

9. 9

   Sprinkle the remaining gruyere and parmesan cheese evenly over the top layer.

10. 10

    Cover the dish tightly with aluminum foil and bake for 45 minutes.

11. 11

    Remove the foil and continue baking for an additional 25-30 minutes until the top is golden brown and bubbly, and a knife inserted in the center meets little resistance.

12. 12

    Let the dish rest for 10-15 minutes before serving to allow the sauce to set and make cutting easier.