1I recommend starting with the filling of this and making the sauce/macaroni/topping while waiting for the components of the filling to be complete (since they take the longest). Preheat the oven to 400 degrees and prepare the garlic to be roasted. Cut off the tops, wrap them in a square piece of foil, pour a tablespoon or two of olive oil on top, and sprinkle with a little bit of salt. Place in a baking sheet and put in the oven. These roast for about 45 minutes, or until the garlic is brown in color and looking soft and delicious. While the garlic heads are roasting, slice the shallots into rings and caramelize in a heavy bottom pan (cast iron works best) in butter. You can occasionally sprinkle the shallots with water if they are getting too sticky or seem like they might be burning. Boil the kale for about five minutes, remove from water, and let cool. Once it is cool, squeeze out as much liquid as you possibly can. Once the kale is dry, the shallots are done, and the garlic is roasted, add them all to a bowl and mix to combine. The garlic and shallots should be soft enough to give the kale a nice coating. Mix in the grated fontina cheese and the filling is done!
2For the sauce, caramelize the onions in butter in another heavy bottom pan on medium until delicious. Add the finely chopped garlic, salt and pepper to taste, and cook for a couple minutes, making sure not to burn the garlic! Slowly add the flour until it becomes soaked by the butter/onions/garlic mixture. Turn the heat up and slowly whisk in milk until it thickens, once the mixture begins to bubble turn the heat down. Add the cheeses and whisk constantly until they have melted.
3At this point you can boil the macaroni until al dente. Prepare the topping by toasting the pine nuts in a heavy bottom saucepan until fragrant. Add the fleur de sel and pine nuts to a processor and pulse until the nuts are finely chopped. Combine the rest of the ingredients and the topping is complete.
4Set the oven to 350. Add the cooked macaroni to the sauce and create the first layer of mac and cheese in the bottom of a 9” by 13” baking dish. Gently add a layer of filling and try to keep the thickness as even as possible. Put a second layer of mac and cheese on top, and finally sprinkle the topping on.
5Bake in the oven for 40 minutes, let sit for 15 before serving.