Plug in your Instant Pot and push "saute" button. Add in ground beef and onion and brown until fully cooked.
Add in taco seasoning, pasta, salsa, chilis, and chicken broth. Stir to combine. Place lid on Instant Pot and seal. Make sure that your valve is in the "seal" position and not the "vent" position.
Push the "manual" button and then set for 5 minutes. The Instant Pot will take about 10 minutes to pressurize and then it will start the 5 minute cooking time.
Once the 5 minutes are up, do a quick release (move the valve from "seal" to "vent") and let all the pressure out. Once the steam has stopped coming out of the vent and the pin in the lid has dropped, remove the lid.
Stir the pasta, add in the cheese and stir until completely combined and cheese is melted. Add salt and pepper as needed and serve.
If desired, top with your favorite taco toppings.
Notes
If desired, top with your favorite taco toppings (I chopped up some tomatoes and then added some fresh cilantro). Pico de gallo would also be delicious on top!