In large skillet, add 1 teaspoon of olive oil to pan. Add onion and garlic, cooking for 3 minutes, or until fragrant.
Add mushrooms, and continue to cook until mushrooms have started to release their liquid - about 8 minutes.
Add kale and fresh sage, continuing to sauté.
When ready to assemble: Preheat oven to 375 degrees. In a 9x11 baking dish, add about 1 cup of butternut squash sauce to coat the bottom. Add lasagna noodles.
Top with mushroom and kale filling, shredded mozzarella cheese, and butternut squash sauce. Continue layering, aiming for 3 layers of lasagna noodles. The last layer of noodles should be topped with butternut squash sauce .Cover with tin foil, and bake for 1 hour and 10 minutes.
Remove from oven, and remove tin foil. Top with fresh mozzarella, and return to oven for an additional 15 minutes, uncovered.
Meanwhile, fry 5 sage leaves to top the lasagna: in a small skillet, heat olive oil over medium high heat. Fry sage leaves until crisp - this only takes about 2-3 seconds! Sprinkle to a paper towel lined plate to cool.
When ready to serve, top with fried sage leaves and freshly shaved parmesan cheese.