Rich and creamy au gratin potatoes with Gruyere, Parmesan, and fresh herbs! The perfect side dish for a week of family meals as they make amazing leftovers and tasty enough for a holiday side dish!
Preheat oven to 400 F.
Use a mandolin to slice your potatoes into thin slices - around 1/8" thick. You can cut with a knife but prep time will increase.
You can place your potato slices into a bowl of water to avoid browning if needed.
Prep your baking dish with cooking spray and layer your potatoes in little stacks (either vertical or horizontal depending on your preference).
Melt butter in sauce pan. Add flour once melted and whisk together for 1-2 minutes. Slowly add in milk and seasonings, continuing to whisk over medium heat until the milk has thickened slightly.
Remove from heat and add your cheese.
***If you are like me, you will be tempted to add more cheese. I don't advise it as it can lead to a different consistency and an "oily" result.
Spoon cheese sauce over potatoes.
Spray foil with cooking spray (to avoid cheese and potatoes sticking on foil) and then over dish. Bake for 60 minutes.
Remove foil and bake for an additional 20 minutes or until lightly browned and potatoes are tender to the fork. Enjoy!
TO REHEAT AU GRATIN POTATOES:
You can either microwave potatoes until hot or re-warm your potatoes in the oven at 350 F for 15 minutes or until hot and sauce is slightly bubbly.