Combine all ingredients except roast and cilantro in a blender. Blend until the mixture is mostly smooth. Pour the mixture into the bottom of a 6-quart or 8-quart Instant Pot.
Cut the roast into 3″ chunks, trimming the fat as necessary. Place the meat inside the Instant Pot, stirring with the sauce.
Place the lid on the Instant Pot, lock and turn the knob to “sealed.” Cook on high pressure for 45 minutes. Use either quick pressure release or natural pressure release to release the steam. Shred the meat with two forks and serve!