Creamy, Cheesy Potatoes Au Gratin

 I remember my mother making this dish often for her family.  It was so good! She didn't always add cheese, because we didn't buy much cheese back then. We couldn't afford it very often.  However, it was still delicious.  If you are craving comfort food, this dish will not disappoint.  She always made it in her CorningWare casserole dishes. I still use those same dishes to make my potatoes au gratin in!

Ingredients

2 lbs. potatoes
2 Tbs. butter
1 onion, cut into thin half circles
2 Tbs. flour
1 can mushrooms, drained. Cut into smaller pieces if desired
1 1/2 c. whole milk
1 tsp. chickem bouillon, (optional)
salt and pepper to taste
1 c. cheese

Directions

Preheat oven to 350°. Butter the bottom and sides of a 9 x 9-inch baking dish.

Thinly slice the potatoes. Try to make the potato slices as thin as possible. We use a mandoline to ensure evenly cut slices, but be careful because the blade is very sharp. 

Put a layer of potatoes and season with salt and pepper. Then add a layer of onion. Repeat adding the layers of potatoes, seasoning with salt and pepper, then layering the onion until it is all in the baking dish.

In a large saucepan, melt butter over medium heat. Whisk in the flour. Cook for 1 to 2 minutes to remove the flour taste. 

Slowly pour in the milk, whisking continuously/  Add the chicken bouillon and mushrooms.  Cook and stir until the sauce is thickened.

Reduce the heat to low. Add the cheese. Cook and stir until the cheese is fully melted.  Season with salt and pepper to taste.

Pour the sauce over the potatoes. 

Cover the baking dish with a lid or use a sheet of aluminum foil.

Bake for 60 minutes, or until the potatoes are tender and the sauce has thickened.  Serve and enjoy!

Notes

You can use cream of mushroom soup in place of the butter, flour, mushrooms, chicken bouillon, and some of the milk.  In a saucepan, add the condensed cream of mushroom soup. Stir in a soup can full of whole milk, Cook and stir over medium heat until the sauce starts to simmer. Do not boil. Add the cheese and stir until melted. 

If you are not adding cheese, simply combine the condensed cream of mushroom soup and one soup can full of whole milk. Stir until smooth.