Go Back

Potato and Yellow Squash Au Gratin

Cheesy Au Gratin made with potatoes and yellow squash.
Prep Time 25 mins
Cook Time 1 hr
Course Side Dish
Cuisine French
Servings 6 Servings
Calories 304 kcal


  • 1 Tablespoon olive oil
  • 1 small onion, chopped
  • 3 Tablespoons butter
  • 3 Tablespoons flour
  • 2 cups whole milk
  • 1 cup cheddar cheese, shredded
  • salt & pepper
  • 3 medium Russet potatoes
  • 3 yellow squash


  • Preheat oven to 350°F and grease a pie pan or 8 x 8 inch pan.
  • Add butter to a large skillet and melt. Whisk in flour and season with salt and pepper. Slowly add milk, ½ cup at a time while whisking. Cook until thickened, about 2 minutes. Stir in cheese until melted.
  • Peel potatoes and slice very thin. Put potato slices right into the sauce as they are peeled so they don’t turn brown. Slice the yellow squash very thin and put into the sauce. Stir to combine and pour into prepared pan.
  • Cover with foil and bake for 1 hour. Uncover and check if potatoes are tender. Depending on how thin the potatoes are sliced it might need more time to bake, another 10-15 minutes. Brown the top under the broiler when potatoes are tender. You can sprinkle with more shredded cheese before browning if you want.
Keyword Cheese, Potatoes, Squash