First, place the walnuts and mushrooms for the meat in a large bowl and cover with hot water. Cover and set aside.
Make the pumpkin ricotta: Place all ricotta ingredients in your food processor and blend on low, pulsing a few times until it reaches a creamy ricotta texture. Transfer to a bowl and rinse out the food processor.
Make the walnut mushroom meat: Strain your mushrooms and walnuts and add them to your food processor with the rest of the meat ingredients. Pulse a few times, then scrape down the sides and pulse again. Repeat this until the mixture has a nice ground meat look. Transfer the meat to a bowl and clean out the food processor.
Now is a good time to make those lasagna noodles if you haven't already! Follow the instructions on the box.
While the noodles boil, make the masala sauce: Heat your olive oil in a medium skillet over medium high heat and add your onions, ginger, and garlic. Sprinkle with a pinch of salt, stir to coat, and cook for 3-5 minutes until the onions are translucent and the mixture is fragrant. Add this mixture to your food processor along with the remainder of the sauce ingredients. Blend on high until fully combined and nice and saucy!
Preheat your oven to 400F and get out a 9x13 baking dish (you can also use two 9x9 dishes).
Assemble the lasagna: Spread 1/2 cup of the masala sauce on the bottom of the dish. Lay down 3 long rows of lasagna noodles, and top with pumpkin ricotta, then walnut mushroom meat. Sprinkle with shredded spinach, top with another noodle layer and repeat once more! Pour another 1/2 cup of the masala sauce over the top of the lasagna and throw it in the oven for 15 minutes. When you take it out, sprinkle a little more shredded spinach on top.
Allow the lasagna to cool a bit before cutting into it, and ENJOY! Store leftovers in an air-tight container in the fridge for up to 5 days or the freezer for up to 6 weeks.