How to Make It
In a medium saucepan, whisk together the milk, flour, 2 tablespoons of the cheese, and 1/4 teaspoon each salt and pepper. Bring the milk mixture to a simmer, whisking, and simmer until slightly thickened, about 3 minutes. Remove the sauce from the heat.
In a medium pot, cook the kale in salted boiling water until tender, about 15 minutes. Drain the kale and finely chop.
Preheat the oven to 450°F.
Drizzle the oil on a baking sheet, then stretch the dough to fit the baking sheet. Spread the sauce evenly over the dough. Remove the sausage from the casings, discarding casings, then crumble the sausage over the pizza. Place handfuls of the kale evenly over the pizza. Bake pizza until the crust is crisp and golden and the sausage is browned, 15 to 18 minutes. Cut into pieces and serve.