Preheat your oven to 375°F (190°C).
In a pan, heat olive oil on medium heat and sauté onions and garlic until translucent.
Add the chicken breasts to the pan and cook until they are no longer pink inside.
Once the chicken is cooked, shred it using two forks and set aside.
In the same pan, add the diced pumpkin and sauté until they begin to soften.
Mix in the spinach and let it wilt.
Season the mixture with salt, black pepper, and a pinch of nutmeg.
In a separate bowl, combine ricotta, half of the mozzarella, and half of the Parmesan cheese.
Time to layer your chicken, pumpkin and ricotta lasagne! Start with a layer of tomato sauce at the bottom of your baking dish.
Place a layer of lasagne sheets on top.
Spread half of the ricotta mixture, followed by half of the chicken-pumpkin mixture.
Repeat the layers until all ingredients are used.
Sprinkle the remaining mozzarella and Parmesan on top.
Cover the baking dish with aluminum foil and bake for 25 minutes.
Remove the foil and bake for an additional 20 minutes or until the top is golden brown.
Let the lasagne sit for 10 minutes before cutting and serving.