Dump diced onion and garlic into the Instant Pot liner.
Add the brown rice and black beans.
Pour the water into the pot liner and add the salt. If using, add the diced green chiles.
Secure the lid with the vent sealed.
Select Manual, using the arrows decrease time to 28 minutes.
Once the time is up you can press cancel or unplug the Instant Pot. Allow the pressure to naturally release. (I let it set for 20 minutes before opening the lid.)
Scoop into bowls and squeeze a lime wedge over bowl and stir. Then add a few slices of avocado for garnish.
