To a large pot of saltedboiling water, add your lasagna noodles. Cook until al dente and according to package directions (usually about 7 minutes). Drain and rinse with cool water (to prevent cooking). Drizzle with oil to prevent sticking (gently toss to coat).
Heat oil in a large pan over medium heat. Add a sprinkle of salt and red pepper flakes. Once hot, add your onion and sauté until softened and lightly browned. About 5-6 minutes
Add garlic, parsley, and oregano. Sauté for 1 minute.
Add mushrooms and cook until they have released their liquid, reduced their size and are somewhat browned (the pan should be almost dry) About 7-9 minutes.
Now add the spinach. You want to cook it until the liquid is released and cooked off. The spinach will reduce in size quite a bit too. About 5-6 minutes.
Remove from heat. Sprinkle with salt & pepper. Taste for additional seasoning and add as needed.
Add a single layer of cooked lasagna noodles (5 noodles). I like to overlap them slightly (*see photo). You will need to cut one of the noodles to fit width-wise.
Now add ½ of your vegan ricotta cheese and spread out evenly with a spatula or back of a spoon.
Add ½ of the spinach and mushroom mixture in an even layer.
Cover the veggies with another layer of sauce.
Add another layer of 5 lasagna noodles.
Repeat every step once more. The last layer of noodles will only have a sauce on top. I like to sprinkle with vegan parmesan cheese. Feel free to leave it plain or top with homemade vegan mozzarella cheese (or store-bought).
Cover loosely with foil and bake for 30-40 minutes, until heated throughout. Now uncover and bake for 15 minutes to make it crispy & lightly brown on top. * After that, if you want a crispier top, you can turn on the broiler for 2-4 minutes. *Watch carefully so it doesn't burn.
Let the lasagna rest for 15 minutes before cutting. Cut with a knife and remove with a spatula. Enjoy!
* The spinach seems like a lot but it will cook down considerably* You'll only need 15 lasagna noodles, but I make the whole box in case some break apart. * Some jarred sauce can be watery which could make your lasagna watery. To thicken it up add 2-3 tablespoons of nutritional yeast to it and heat it on medium heat for 2-3 minutes. *You can also use cornstarch to thicken instead. Make a slurry with 1 tablespoon of cornstarch and 1 tablespoon water. Mix them together and add to simmering sauce. Whisk well and let cook for 2-3 minutes. * Taste jarred marina for salt. Add more if needed. * I like my lasagna saucy so I add it generously. Feel free to use less. * Nutritional info includes vegan ricotta cheese.