Slice the seitan and put into the food mixer. Finely mince the vegetables and stir-fry for about 5 minutes in a non-stick pan with some oil. Add two spoons vegetables to the seitan and mix.
Cook the tomato pulp on a low flame for 15/20 minutes, adding the spices of your choice.
Now shape some meatballs using the mixed seitan, adding some breadcrumbs of flour if it’s too wet. Put seitan meatballs into the tomato sauce and cook for 5 minutes. Cook spaghetti in abundant, salted water; when ready, drain the pasta and put in the pan with sauce and meatballs.