Creamiest Cheesy Potatoes au Gratin

Yields: 8 Servings Difficulty: Easy Prep Time: 20 Mins Cook Time: 30 Mins Total Time: 50 Mins

Ingredients

0/12 Ingredients
Adjust Servings
    Cream Sauce
  • Potatoes au Gratin

Instructions

0/7 Instructions
  • Preheat ove to 375. Set out a 9x13-inch pan or other large backing pan with tall sides.
  • Saute the onions and garlic: In a medium skillet add oil and heat over medium-high eat until shimmering. Add the onions and cook, stirring often, until softened and beginning to color slightly. Stir in the garlic and remove from the heat. Stir occasionally as the onions continue to caramelize lightly in the residual heat.
  • Make the Cheesy Cream sauce: Melt the butter in a large saucepan over medium-high heat. Sprinkle the flour over the butter and whisk until completely smooth. Don't take any shortcuts, you don't want any lumps! Reduce the heat to medium and cook, whisking constantly for 2 minutes, this helps the sauce be smoother and gets rid of the raw flour flavor. Add the milk, cream and salt, whisking until smooth. Turn the heat back up, bring back to a boil and cook whisking constantly until thickened.
  • Stir in the sauteed onions and garlic. Add the Cheddar (half at a time) and the Parmesan cheese. Stir until the cheeses are fully melted. Keep the sauce warm over very low heat, stirring occasionally while you prep the potatoes.
  • Prepare the Potatoes: Peel the potatoes and cut into thin slices. Stir the potatoes into the cheese sauce and pour into the prepared backing dish. Cover with foil and bake for 30 minutes.
  • Remove the foil and cover from the pan, sprinkle the top with the remaining Parmesan and return to the oven. Continue baking for about 20 minutes or until the casserole is bubbling, the top is golden brown and the potatoes are tender when you insert a knife or fork.
  • Remove the pan from the oven and let set for about 15 minutes before sprinkling the parsley on the top and scooping servings.

Notes

Make Ahead

You can make the se potatoes up to a couple of days in advance. Reheat uncovered in the microwave or oven until bubbling around the edges and the center is heated through.