Preheat oven to 350°F Cook the pasta until al dente. While pasta is cooking, heat the oil in a pan over medium heat. Add the peppers, mushrooms and seitan. Sauté until the vegetables soften and the seitan begins to brown, then take off the heat.
In a small sauce pan, bring the vegetable stock to a boil. Turn the heat down to a simmer and slowly whisk in the flour. Once combined, add the cream cheese and stir until it is combined and the sauce is thick and creamy. Take off the heat.
Grease a 9x9 baking dish with oil or margarine. Combine the cooked pasta, vegetables, seitan, sauce and 2 tsp of the Parma. Pour the mixture into the baking dish, top with the vegan mozzarella, cover with foil and bake for 25 minutes.
When the 25 minutes are up, remove from the oven, top with the rest of the Parma and let cool for 5-10 minutes. Cut into squares to serve.