Heat the olive oil in a large skillet over medium heat. Add the onions and cook, stirring often, for 20-30 minutes, or until tender and golden brown.
Meanwhile, in another skillet over medium heat, cook chicken and basil sausage making sure to break it up into crumbles. Add the crushed fennel seeds and crushed red pepper flakes and mix until well combined. Once the meat is brown remove from heat; set aside.
Heat a little more olive oil in the same skillet then add the kale along with 2-3 tablespoons of water. Cook, stirring often, until it starts to wilt, about 3-4 minutes. Add the minced garlic then season with sea salt and freshly cracked pepper, to taste; cook, stirring constantly, for 1 minute. Remove from heat.Combine the caramelized onion, garlicky kale, and chicken sausage together in a bowl; stir until well combined. Set aside.
In a large bowl, add ricotta, egg, 1/2 cup of mozzarella cheese, Asiago cheese, fresh chopped basil, nutmeg, sea salt, and freshly cracked pepper, to taste. Combine until mixed thoroughly.
Preheat the oven to 350 degrees. Coat a 9 x 13 inch baking pan cooking spray then layer with just enough marinara sauce to cover the bottom of the pan. Cover the marinara with lasagna noodles covering the entire bottom of the pan with them. Spread half of the ricotta mixture on top of the noodles, then spoon half of the chicken/kale/onion mixture on top; spoon some sauce on top of the meat mixture. Add more noodles to cover the meat mixture then top with the remaining ricotta mixture followed by the last of the meat mixture. Finish with a layer of noodles and remaining sauce. Sprinkle with mozzarella cheese and sprinkle the top with dried basil, to taste.
Bake covered in oven for 50 minutes. Uncover and bake for 10 minutes. Let the lasagna cool for 10 minutes before slicing and serving. Enjoy.