In a saucepan, saute onion in water or oil over medium heat for about 5 minutes. Add mushrooms and garlic and stir, cooking for another 2-3 minutes.
Add tomatoes and stir. Reduce heat and simmer for 30-25 minutes.
Make the no cheese sauce and set aside.
Preheat the oven to 350F.
Transfer about 2 cups of the tomato mixture to a blender and pulse a few times until somewhat smooth. Ladle just enough sauce into a 10″x13″ lasagna pan to lightly coat the bottom.
Lay down a layer of lasagna noodles, followed by about half the bag of Boca crumbles.
Using a slotted spoon to drain the excess liquid, spoon on a layer of the onion and tomato mixture.
Drain and crumble the tofu, and add a layer of crumbled tofu (about half of the block).
Pour on a layer of no cheese sauce.
Add a layer of noodles and tomato sauce, then repeat layers of Boca crumbles, tomatoes, tofu, and no cheese sauce.
Finish with a layer of noodles topped with the rest of the tomato sauce, Boca crumbles, and no cheese sauce.
Cover the lasagna with foil and bake at 350F for 40-45 minutes, until the noodles are cooked.
Allow to cool for at least 30 minutes before serving.