Set your Instant Pot to the "Sauté" function. Add the lean ground beef and cook, breaking it apart, until it's fully browned. Once cooked, turn off the Instant Pot and carefully drain any excess grease for a healthier dish. Return the beef to the pot.
Evenly spread the rotini pasta over the browned beef. Sprinkle the chili powder and cumin directly onto the pasta. Gently pour the enchilada sauce and beef broth over everything. Ensure the pasta is just barely covered by liquid; if not, add ¼ to ½ cup of water. Crucially, do not stir at this stage. Finally, spoon the rinsed black beans on top – again, no stirring!
Secure the Instant Pot lid and make sure the vent is set to the "Sealing" position. Set your Instant Pot to "Manual" or "Pressure Cook" (High Pressure) for 4 minutes.
Once the cooking time is up, allow a 5-minute natural pressure release. After 5 minutes, carefully perform a quick release of any remaining pressure by turning the vent to "Venting."
Once the pressure valve drops, open the lid. The mixture might look a bit soupy at first, but don't worry – it will thicken! Stir in the shredded cheddar cheese until it's completely melted and creamy. Let it rest for a few minutes to allow the sauce to thicken further. Serve hot, and for an extra touch, you can top it with a little more shredded cheese!