Peel and slice the potatoes. Soak 'em in water to avoid browning. Preheat the oven to 350°
Melt the butter in a pot.
Add the flour.
Whisk the melted butter and flour together until smooth.
Add the milk. Whisk together.
Let it boil slightly.
Add the shredded cheese.
Whisk the whole thing together until cheese has melted and the mixture has incorporated well. Season with garlic powder + S&P.
Lightly brush the bottom of the pan with oil or use Pam Spray. Spread some of the cheese sauce into the pan.
Assemble the sliced potatoes into the pan.
Pour the remaining cheese mixture on top. (*Add more shredded cheese and Panko breadcrumbs on top if you like)
Cover with foil. Bake it in the oven for 45minutes.
Carefully take out the foil after 45minutes. Stick it in the oven for another 5minutes.