Add the tomato sauce, herbs, pepper flakes and salt and mix in. Switch off saute. Add pasta and water and mix well to dislodge any stuck bits. Press the pasta into the sauce so the pasta is well covered in the sauce.
Alternatively, add water, veggies if using, herbs, salt and mix in. Then add tomato sauce on top and pasta and press just to cover the pasta but dont mix. (some IPs are more prone to burn errors that others so try both to see which works. Also see tips above)