1 medium butternut squash, peeled and seeds removed, diced into 1/2″ cubes
12 sheets of no-boil lasagna sheets
1/2 cup Parmesan cheese
1/2 bunch sage leaves
for the béchamel sauce:
2 Tbs olive oil
1/8 tsp fresh nutmeg
4 Tbs all-purpose flour
2 1/4 cups whole milk
1/2 cup siggi’s Plain skyr
1/2 cup mozzarella, shredded
1/4 cup parmesan, shredded
1 tsp salt
Heat 1 Tbs of olive oil in a medium heavy bottomed pan. Toss the squash in the oil. Season with salt and pepper. Add about 1 inch water to the pan and cover to steam until squash is soft enough to purée, about 15 minutes. Purée half the squash with enough pan water to make a fairly thick purée. Set aside remaining squash.
Béchamel sauce: Heat the milk and nutmeg in a saucepan until just steaming. Remove from heat.
Roux: Heat the olive oil and butter in a pan. Once melted, sprinkle flour and stir until incorporated. Cook at a slight bubble for about 7-10 minutes, stirring constantly. Slowly whisk the warm milk into the roux. When the consistency is as thick as cream soup, stir in the skyr and turn the heat down. Slowly whisk the cheese into mixture until thick and creamy. Season with salt & pepper to taste.
Prepare lasagna pan. Grease a 8x 8 pan with olive oil or butter. Layer about 1/2 cup of the purée, on the bottom of the pan. Add a layer of noodles. Layer on the remaining purée, 1/2 of the cubed squash and 1/3 cup of the béchamel sauce. Scatter the sage leaves (about 4 throughout the layers). Layer 1/2 cup parmesan. Repeat with the layers, ending with the béchamel sauce on top. Sprinkle with Parmesan.
Cover with aluminum foil and bake at 350°F for about 45 minutes. Uncover and continue baking for 15 minutes or until golden brown.