Clean the kale by removing the stems. Sauté one onion, then add the kale and cook for 5 minutes. Let any excess water evaporate. In a separate pan, sauté the other onion and the sausage (remove the casing and break it up) to make a ragù.

Add the kale to the sausage mixture and deglaze with the white wine. In a separate container, whisk the flour into the cold milk until smooth.

Add the milk mixture to the warm sausage ragù and return to the heat. Bring to a boil and cook for a couple of minutes until thickened. Butter a baking dish and assemble the lasagna, making just two layers of noodles.

Halfway through layering, add some fontal cheese. Add another layer, then top with thin slices of fontal (use a vegetable peeler) and a sprinkle of grated Parmesan.