Preheat the oven to 375˚F. Coat the inside of an 8-inch square (1 1/2-quart) baking dish or pan (or six 8-ounce ramekins) with olive oil. Set aside.
Fill a 4- to 5-quart pot about three-quarters full with water and add 1 tablespoon of the salt. Bring to a boil and add the pasta. Cook, stirring once or twice, until tender but firm, about 8 minutes, and drain. Reserve the pot.
To prepare the kale, remove the stems. Cut 4 whole leaves into quarters and coarsely chop the rest. In a large skillet, heat 2 tablespoons of the oil over medium heat. Add the onion and cook for 5 minutes, or until soft. Add the chopped kale and garlic and cover and cook, stirring occasionally, until the kale is tender, 5 to 7 minutes. Stir in the red pepper flakes and 1/2 teaspoon of the salt and set aside.
Place the quartered kale leaves in a small bowl. Toss with 1 tablespoon of the olive oil, half the pecorino and add salt and black pepper to taste. Set aside.
Using the same pot you used to cook the pasta, heat the remaining 2 tablespoons of oil over medium heat. Slowly whisk in the flour and stir constantly until a paste forms, 30 to 45 seconds. Continue stirring for 1 to 2 minutes, until the mixture starts to darken slightly and smell a bit nutty. Slowly whisk in the milk, cream, and the remaining ¾ teaspoon salt and cook until the mixture starts to thicken and is just beginning to bubble around the edges, 5 to 7 minutes. It should be thick enough to coat the back of a wooden spoon. Add 3 cups of the Fontina, the remaining pecorino, the cayenne, and nutmeg and stir until the sauce is smooth but not too runny. It should be similar in texture to cake batter. If it’s soupy, continue cooking until it thickens.
Add the pasta and chopped kale mixture, and stir to combine. Pour into the prepared baking dish. Sprinkle the remaining cheese on top. Distribute the quartered kale leaves over the top. Place the dish on a rimmed baking sheet and bake until bubbling and golden brown, about 30 minutes. Let cool for 15 minutes before serving.
Add-ins: Dried currants: Soak 1/2 cup currants in hot water for 15 minutes. Drain and add to the sauté pan with the kale and garlic.
This recipe is excerpted with permission from <a href="http://www.amazon.com/gp/product/1449426468/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1449426468&linkCode=as2&tag=craftfocom-20">"Mac & Cheese, Please! 50 Super Cheesy Recipes"</a> by Laura Werlin and published by Andrews McMeel Publishing, LLC.