Press the Saute button on the Instant Pot. Add the ground beef to the pot and season with salt and pepper. Cook, crumbling the meat, until browned. Press Cancel to turn off the saute function.
Add the bell pepper, crushed tomatoes, salsa, corn, taco seasoning and chicken broth or water to the pot. Stir and scrape up any bits that are stuck to the bottom of the pot.
Add the pasta to the pot and press it down into the liquid but do not stir. Close the Instant Pot lid and turn the steam release valve to the sealing position. Set the cook time to 4 minutes at high pressure (see note below about pasta cooking time).
The Instant Pot will take about 15 minutes to reach pressure and then the cook time will begin counting down. When the cook time ends, immediately do a controlled quick release by slowly turning the steam release valve to the venting position using the handle of a long spoon. Once all of the steam has escaped and the pin drops down, open the Instant Pot lid. The pasta may look liquidy but give it a stir and the extra liquid will be absorbed by the pasta.
Stir in the cheese and serve.
