Sheet Pan Pasta Gratin with Kale

Preheat oven to 425 degrees F (220 degrees C). Bring a large pot of water to a boil. Add Kosher Salt (1 Tbsp) . Boil Pasta (13 oz) for 2 minutes less than the box's suggested al dente time. Drain. Do not rinse. Set aside.

Meanwhile, melt Unsalted Butter (1/4 cup) over medium-high heat in a medium saucepan. Add All-Purpose Flour (1/4 cup) , whisking constantly for about a minute. Add Milk (2 cups) and Water (2 cups) , whisking to remove any of the flour-butter mixture from bottom of pan. Bring to boil, then reduce heat and gently simmer. Kosher Salt (1 1/4 tsp) and Freshly Ground Black Pepper (to taste) . Simmer until mixture begins to thicken, about 20 minutes.

Chop the Kale (9 cups) into small pieces. In a large mixing bowl, toss pasta with thickened bechamel and Parmesan Cheese (1 1/2 cups) , then fold in chopped kale.

Line a rimmed sheet pan with a sheet of parchment paper. Spread macaroni mixture over top. Distribute Fontina Cheese (1 1/2 cups) over the top.