Set the pot on saute mode, and allow to heat. Add 1 Tbs olive oil, and saute the onion until softened, then add the garlic and cook for about 30 seconds.
Add the ground beef, and brown. Drain if necesary
Add the spaghetti (I break it up and put it in the pot in varying directions - a criss cross pattern works well!).
Pour the pasta sauce over the top, and then pour the water around the sides. Sprinkle over the Italian seasoning. DO NOT STIR.
Place the lid on the instant pot, and set to seal, and cook on high pressure for 8 minutes.
Do a natural pressure release for 5 minutes, then perform quick release.
Remove the lid, stir the food until well combined.