Start by pressing sauté mode on the instant pot then add in oil and wait 3 minutes.
Once your oil is hot, add in your ground beef and sauté, during cooking, with the help of a wooden spoon, break it into small pieces. Cook the beef until fully browned.
Next, add in chopped onion and diced bell pepper and cook for another 5 minutes until your vegetables are tender.
Add in drained kidney beans, diced tomatoes, broth, chili powder, cumin, salt, pepper, elbow macaroni, and 1 cup of shredded cheese. Give everything a good stir.
Close the lid, and place the valve in sealing mode. Then select the high pressure and cook for 5 minutes. Remember that it will take about 20 minutes of the pressure to rise and start cooking.
Once cooked, release the pressure immediately, open the lid and stir it.
Serve hot and add more cheese and green onion.