Wisconsin Sharp White Cheddar, Yukon Gold Potato and Leek Gratin

1/4 cup butter
3 cups (5-8 large) leeks, white part only, cleaned and chopped
3 lb. (about 8 large) Yukon gold potatoes peeled, very thinly sliced
Salt and freshly ground black pepper
4 cups (16 oz.) Sargento Artisan Blends® Shredded Wisconsin Sharp White Cheddar Cheese
2 cups heavy whipping cream

Melt butter in a large skillet over medium-low heat. Add leeks; sauté 10 minutes or until leeks are tender, but not browned.
Butter a 13x9-inch glass baking dish. Arrange 1/4 of the potato slices in bottom of dish. Season potatoes lightly with salt and pepper. Spoon 1/4 of the leeks over potatoes; top with 1 cup cheese and 1/2 cup cream. Repeat layering three times with remaining ingredients.
Bake in a preheated 350°F oven 1 hour and 15 minutes or until potatoes are tender when pierced with a sharp knife.