3 med russet potatoes, thinly sliced (about 3 cups)
3/4 cup thinly sliced onions
1 cup 2% milk
1 Tbsp all-purpose flour
1/2 tsp salt
1/4 tsp freshly ground black pepper
1 1/2 tsp melted butter
Preheat oven to 425F. Lightly coat a 9-inch square baking dish with a small amount of canola oil.
Place half of the potatoes in the dish and cover with onions. Top with remaining sliced potatoes.
In a blender, combine milk, flour, salt, pepper and butter. Blend until well mixed. Evenly pour over the potatoes.
Cover and bake for 45 minutes. Remove cover and bake an additional 15 minutes, or until potatoes reach desired crispness on top.