Potatoes and Onions and Cheese, Oh My

Ingredients:

2 tablespoons butter
4 -6 potatoes depending on size
2 onions
2 cups whole mushrooms
2 tomatoes sliced
salt and pepper to taste
2 tablespoons butter
2 tablespoons flour
200 g cheddar cheese grated
400 ml milk
50 g cheddar cheese grated See a href=https//wwwgeniuskitchencom/recipe/peters-cheese-sauce-207024Peter's Cheese Sauce/a for preparation of sauce

Preheat oven to 200C/400F
Generously butter the inside of a 9X13 baking dish and set aside
Peel the potatoes and thinly slice along with the onions and mushrooms using a food processor or mandoline
Layer half the potatoes into the bottom of the baking dish then half of the onions followed by half the mushrooms Season with salt and pepper Repeat layers with remaining veggies and season with salt and pepper
Pour cheese sauce over potatoes and cover with aluminum foil
Bake for 1 1/4 hours Remove from oven and take foil off Put a single layer of sliced tomatoes on top if using Sprinkle with remaining 50g cheese and return to oven for 15 minutes turning on broiler/grill for the last 3-5 minutes to brown cheese
Allow to sit 10 minutes before serving