In a large skillet, drizzle the olive oil over medium heat.
Add the onion and cook, stirring occasionally, until beginning to soften.
Stir in the garlic and cook until just fragrant, 30 seconds-1 minute.
Stir in the mushrooms and continue to cook until softened and most of the moisture has evaporated.
Add the kale and cook, stirring, just until tender and vibrant green, about 2 minutes.
Remove the skillet from heat and set aside to cool to room temperature. Once cool enough to handle, squeeze out any excess moisture.
In a large bowl, combine the ricotta, mozzarella, Parmesan, egg, parsley, salt, and pepper.
Add the cooled kale mixture and fold until evenly combined.
Preheat oven to 350˚F (180˚C).
In a 9×13 inch (23 x 33 centimeter) baking dish, spread about 1 cup (240 milliliters) of the tomato sauce to cover the bottom.
Bring a large pot of salted water to a boil.
Once boiling, add the lasagna noodles and cook until barely tender, al dente, and softened enough to roll without snapping.
Gently drain and allow to cool just enough to handle.
When cool enough to handle, lay the noodles flat and lightly dab with a towel remove any remaining water.
Spread a thin layer of the kale cheese mixture across the surface of a cooled lasagna noodle. Roll the noodle up, short end to short end, and place seam side down in the prepared baking dish. Repeat with the remaining noodles and filling.
Cover the rolls with remaining tomato sauce along with a sprinkling of mozzarella and parmesan as desired.
Cover the baking dish with foil and bake in the preheated oven for 25 minutes.
Remove the foil and continue baking for another 10-15 minutes, until the cheese is melted and bubbly.
Serve the Mushroom Kale Lasagna Rolls warm from the oven with a sprinkling of additional fresh parsley, if desired.