Turn your Instant Pot to the Saute setting. Add oil and onions. Cook 2-3 minutes, until translucent.
Add carrots, celery, beans, liquid, spices, chipotle chili, and cocoa powder (if using). Turn Instant Pot to manual setting and set to 55 minutes. Be sure the top knob is sealed.
When the chili is done cooking, do a quick release (or wait for the slow release if you prefer a softer chili).
If using, stir in half a 10oz bag of frozen corn and masa harina. Let warm for several minutes.
Add extra salt if needed. Serve with any toppings you like.
Notes
Cocoa Powder: I go back and forth on using this. It adds depth, but also a hint of sweetness that I don't always want. Feel free to go with your mood.Masa harina: This corn flour can be used to thicken your chili or to add a bit of a corn flavor.Slow cooker adaptations: Saute onion in a pan on the stove before adding to the slow cooker with other ingredients. Cook on high for 4-5 hours or low for 8 hours, and add an extra cup of water.