Step 1:
Preheat the oven to 400 degrees F. Peel the potatoes and place in water.
Step 2:
With a mandolin, cut the potatoes into 1/4–inch slices. Beat together cream, milk, garlic powder, salt and pepper. Coat the inside of large baking dish with extra virgin olive oil.
Step 3:
Place sliced potatoes at the bottom of the dish. Add salt and pepper, slices of onion and cheddar cheese. Add several layers, then add the cream mixture. Cover potatoes and bake for 20 minutes, then uncover and bake another 60 minutes or until brown on top. Sprinkle remainder of cheddar cheese and Parmesan cheese. Sprinkle parsley just before serving.
Step 4:
Serve and enjoy!
4 servings