Place the spaghetti in the instant pot and cover with tomato sauce. Give it a good stir until the pasta is covered, then add the water and salt. Stir again to be sure the pasta is fully submerged.
Put the lid on the instant pot and set the pressure to high for 8 minutes.
Once complete, allow the pressure to naturally release for 5 minutes, then manually release it the rest of the way.
Give the pasta a good stir and serve with your favorite spaghetti toppings.
Instructions (for the meat version):
Turn the instant pot to the saute setting. Heat the oil then add the meat, garlic and diced onion. Break apart the meat as you cook and continue sauteeing until the onion is translucent and the meat is fully cooked.
Follow the instructions above for the rest of the recipe.