Preheat the oven to 350°F. Line a square baking pan with parchment paper and grease with nonstick cooking spray. Set it aside.
Bring a pot of salted water to a boil and cook the lasagna noodles for 8 minutes or until al dante.
Once the lasagna noodles are cooked, immediately lay them out in a single layer on a parchment sheet sprayed with nonstick spray.
In a large bowl, whisk together the ricotta, pumpkin, ½ cup of parmesan, egg, salt, black pepper, and dried sage. Whisk until combined. Place 3 tablespoons of the mixture on each lasagna noodle.
Spread the ricotta filling out all over the noodles. Take 1 cup of shredded mozzarella and sprinkle it evenly over the filling on each lasagna noodle. Keep the remaining cheese for the top.
Roll up each lasagna noodle tightly from the end.
Heat the butter in a large skillet over medium heat. Once sizzling, whisk in the flour and let it cook for 2 to 3 minutes, until fragrant and golden. Slowly whisk in the milk, stirring the entire time to avoid lumps. Whisk constantly until the mixture thickens, for about 3 to 4 minutes. Reduce the heat to low and stir in a pinch of salt and pepper along with nutmeg.
Ladle ½ cup of sauce in the bottom of a square baking dish.
Place the lasagna roll ups seam-side down in the dish. Pour the remaining sauce over top of the rollups. Sprinkle the remaining 1 cup of mozzarella on top along with a sprinkle of parmesan cheese. Bake for 25 to 30 minutes, until golden and bubbly.
Remove the lasagna roll ups from the oven and serve arugula salad.
For the Salad
Place the arugula, cherry tomatoes, and carrots in a large bowl.
In a small bowl, whisk together the dressing ingredients.
Drizzle the dressing over the arugula mixture to moisten it, then toss to combine.
Sprinkle Parmesan and chopped parsley. Serve immediately with a drizzle of extra dressing as desired.