Turn IP on to saute mode and add your olive oil and wait for it to read HOT. Once hot, add in your onion and garlic and saute until fragrant.
Add in your ground beef, Italian seasoning, and salt and pepper and cook until all the beef is browned. Drain any excess grease.
Add beef broth to pot and scrape of any stuck-on bits from the bottom of the pot. This will prevent you from getting any burn notice.
Break spaghetti noodles in half and layer them over the ground beef. Do small layers at a time and alternate the direction of noodles for each layer in a criss-cross pattern. Then pour water over the noodles.
Pour the can of diced tomatoes (undrained) and the pasta sauce over the center of the noodles.
Close the lid and set your valve to sealing. Pressure cook on high for 10 minutes. When the timer is finished allow it to naturally release for 1 minute then quickly release the pressure.
It will look like there is a lot of liquid but just stir the pot so everything is mixed together. Let it sit for 5-10 minutes. Top with parmesan.