Turn on the Instant Pot to 'Sauté' and allow it to heat up for a few minutes.
Add the ground beef to the pot and sauté until it is fully cooked.
Next, add the dry minced onion, Italian seasoning, garlic powder, salt and pepper to the ground beef and mix well.
Pour the beef stock over the cooked ground beef in the pot, stir well and then cancel the 'Sauté' mode.
Add the spaghetti pasta to the pot. It is not necessary to fully mix the pasta into the ground beef. Just gently push it down into the liquid using a spoon or spatula.
Layer the spaghetti sauce on top of the pasta without mixing it in.
Close the Instant Pot, adjust the pressure release valve to 'Sealing' and set the pot to 'Manual' or 'Pressure Cook', High Pressure for 5 minutes. Once the cooking time has finished, allow for a 2 minute NPR (natural pressure release).
Release the remaining pressure after the two minutes have completed. Once all the pressure has been released, open the pot and give all of the ingredients a good stir. You may find a few strands of pasta stuck together, which is normal. Use a spoon or spatula to break them up.