Pre heat oven to 400

With the mandolin, slice all of your potatoes Approximately 1/8th " (you can throw away the end pieces).

In a medium sized bowl, whisk together heavy cream, garlic, and melted butter

In a 9 x 12 pyrex dish and spray with a non-stick spray. Put a layer of sliced potatoes first. Sprinkle with a little salt & pepper. Use 1/3 portion gruyere & cheddar.

Repeat the previous step until all potatoes are done and are finished with a top layer of potatoes. You should have about 3 - 4 layers of potatoes and cheeses. Pour 1 /3 cream mixture over.

Repeat process for 2 more times. Do NOT cover with remaining cheese. We'll save this for the last step.

Cover with foil and bake for approximately 1 hour and 15 minutes.

Remove foil and cover top with the remaining cheese. Place back in oven for an additional 15 minutes, or until the cheese is golden brown.

Once removed from oven, allow to rest for 10-15 minutes before serving.