Heat olive oil over medium high heat. Add onions and garlic and sauté until softened. Stir frequently so it doesn’t burn.
Add the butternut squash puree and dash of nutmeg to the pan.
Next, add some of the vegetable stock or to thin the sauce a bit. You want it to be similar in consistency to a thick marinara sauce.
Add 1/4 cup parmesan cheese and stir to combine. Add salt and pepper and adjust as needed.
Squeeze as much of the liquid as you can out of the spinach.
Combine the spinach, parmesan, lemon juice, ricotta, Italian seasoning, 1/4 cup parmesan and Greek yogurt. Stir to combine. Add salt and pepper and adjust as needed.
Assemble and cook the lasagna
Spray the baking pan you will be using with baking spray or lightly coat with oil.
Spread 1/4 of the butternut squash sauce in the bottom of the pan.
Next place a single layer of lasagna noodles. You may need to cut the noodles to fit your pan.
On top of the lasagna place half of the spinach mixture and spread out evenly.
Top that layer with another ¼ of the squash mixture and ¼ cup of mozzarella cheese.
Repeat with another layer of the lasagna noodles, the remainder of the spinach mixture, another ¼ of the squash mixture and ¼ cup of mozzarella cheese. Top that with another layer of lasagna noodles.
Top with remainder of the butternut squash sauce and finish with the remaining 1/2 cup of mozzarella cheese.
Place the baking dish in a hot oven and cook for 30 minutes or until the cheese is lightly brown and the dish is heated through.
Use regular noodles in place of the oven-ready lasagna sheets. You will need to boil these first following the instructions on package. Be sure to not overcook the noodles, they should be al dente as they will cook more once in the oven. When they are ready, remove and layout flat to dry out.