See Notes

Preheat the oven to 350 degrees.

Butter a 12 cup or 7x12" casserole dish.

Cut off the end root and greens from the leek.

Slice the middle portion into thin rings and place in a bowl of cold water.

Swish the leeks around and break up the rings to release any dirt.

Pull the leeks straight out of the water. Repeat with fresh water if any dirt lingered on the leeks.

Pat dry.

Peel the potatoes and place in a bowl of cold water, completely submerged to keep the potatoes from browning.

Using a food processor or mandolin, slice the potatoes 1/8" thick.

In a heavy bottomed dutch oven, add the olive oil and bring to medium heat.

Once shimmering add the leeks and saute until translucent, about 3 minutes.

Add the garlic and cook for one more minute, stirring continually.

Add the potatoes, cream, milk, and bay leaf to the pot and simmer for 15 minutes or until the potatoes begin to turn tender and the cream is starting to thicken.

Remove from heat and discard the bay leaf.

Starting on the outside edge of the pan, using a fork, gently lift the potato slices into the casserole dish, overlapping the potatoes all around the edge and circling into the middle until the entire pan is covered in potatoes. This should take half of your potatoes.

Sprinkle with half of the salt, a few cracks of pepper to taste, and half of the nutmeg.

Mix the two cheeses together and sprinkle 1/3 of the cheese over the potatoes.

Repeat the overlapping potatoes then pour any of the leftover cream over the top then seasoning and cheeses.

Bake at 350 for 20 minutes or until the cheeses are bubbling and potatoes tender.

Rest for 5 minutes before serving.