Preheat oven to 400 degrees F.
Cook Ziti according to package directions and drain when finished.
Mince the seitan and mushrooms in a food processor until course and crumbly. Pour mushroom and seitan mixture into a large saucepan and stir in tomato sauce. Bring to a simmer over medium heat and cook for about 10 minutes.
In a food processor, puree the tofu, basil, lemon, olive oil, and salt and pepper until consistancy is similar to ricotta cheese.
Spread some of the tomato-seitan mixture into the bottom of a 13 x 9 inch baking pan so that it coats the bottom.
Combine the drained Ziti, tofu mixture, and remaining tomato-seitan mixture in a large bowl and mix gently to combine all ingredients. Spread evenly into the 13 x 9 inch baking pan and bake for 15 minutes.