Preheat oven to 400 degrees.
Line a 6X6 casserole dish with a layer or aluminum foil followed by a layer of parchment paper. This makes for easy clean up! Then drizzle avocado oil into dish and swirl to evenly coat the bottom surface.
Heat a large nonstick skillet over medium-high heat and add ground chicken and spinach. Season with salt, pepper, Italian seasoning, and juice of lemon. Occasionally stir until evenly cooked.
While the chicken cooks, prepare cheese mixture. In a medium bowl, combine Kite Hill cream cheese, ricotta, unsweetened nut milk (I used oat), and an extra pinch of salt and pepper to taste. Set aside mixture.
Next, cut zucchini into wide, thin slices. Set aside.
When chicken is fully cooked, turn off heat and carefully transfer to another mixing bowl to cool.
Begin lasagna assembly. Spoon a few tablespoons of marinara sauce at the bottom of the oiled casserole dish and spread out evenly.
Add a layer of the lasagna sheets, making sure to cover the entire surface of the dish.
Next, dollop a few tablespoons of the cheese mixture on top of the lasagna sheets. Not too thick, but not too thin of a layer.
Spoon a layer of ground chicken. This recipe is designed to be high-protein, so don't be shy with the portioning here!
Lastly, add enough of your zucchini slices to create the last thin layer. Make sure none of the slice overlap, so that they all cook evenly.
Finish with another layer of sauce.
Continue repeating your layers starting with lasagna sheets, cheese mixture, ground chicken, zucchini slices, and sauce until you fill up your casserole dish. End your last layer with sauce then any remaining cheese mixture.
Cover your casserole dish with aluminum foil and bake in the oven for about 35 minutes.
Carefully remove casserole dish from oven, remove foil, and lower oven temperature to 375 degrees.
Continue to cook lasagna for another 15 minutes. It should be getting golden brown and bubbly.
Remove lasagna from oven and allow to cool and set on counter for about 10 minutes.
Cut into thick squares and top with a sprinkle of red pepper flakes. Dig in!