Cheesy Au Gratin Potatoes with Yellow and Sweet Potatoes
Leah Beyer
This cheese scalloped potatoes recipe uses both yellow potatoes and sweet potatoes along with onions, white sauce, and lots of cheese to make the ultimate cheesy au gratin potatoes.
Slice potatoes with a mandoline. Slice the onions. Mix together in a bowl and season with salt and pepper.
Melt butter in a sauce pan with the minced garlic. Stir in the flour and let cook for one minute.
Slowly add the heavy cream, stirring constantly. Then pour in the milk. Season with salt and pepper. When the white sauce just begins to boil, remove from heat and stir in thyme.
Make the casserole. Start with a quarter of the white sauce and shredded Grueyere cheese. Layer a single layer of 1/3 of the potatoes and onions. Pour the next quarter of the what sauce and cheese, then potatoes and onions. Repeat again. Then top off with the cheddar cheese as well.
Cover with aluminum foil and bake for one hour. Remove the foil for the last 10 minutes of baking.
If potatoes are not soft to a fork at an hour, keep cooking until potatoes are soft.