Heat your oven as high as it will go (500 to 600 degrees F) with a pizza stone set on the bottom floor for 30 minutes before cooking the pizza.
Slice the sunchoke as thinly as possible with a mandolin into a bowl. (You should get enough pieces to make a thin layer that covers the whole pie.) Toss together the rosemary, Parmigiano-Reggiano, kale, a generous dash of olive oil and a generous pinch of salt, coating everything evenly and massaging the kale to soften it up. Taste for salt and adjust if necessary.
Stretch out the dough into a 12-inch round, first pinching a hearty edge for the crust, then gently stretching to reach 12 inches. Generously flour a pizza peel and lay down the round. Quickly lay down the mozzarella, then an even layer of the sunchokes, followed by the kale. The kale should not cover the pie evenly like the sunchokes, but add an accent of color and crunchiness. Top the pie with the fontina and slide onto the pizza stone.
Cook until the pie is evenly browned, 6 to 8 minutes. Pull the pie onto a flat metal pie pan or the underside of a baking sheet so it's easy to slide off onto a cutting board. Cut the pie into 6 even pieces and drizzle with creme fraiche.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.