Remove the corned beef from its packaging and place in the Instant Pot.
Sprinkle the packet of spices that came in the package over the beef.
Pour the stout beer into the Instant Pot.
Secure the lid and set the seal to sealing.
Cook on Manual High Pressure for 90 minutes (1 hour 30 minutes).
When completed cooking, let it Naturally Release for 20 minutes and then Manually Release the remaining pressure.
Remove the corned beef from Instant Pot and shred either using two forks, hands, or a mixer.
Pour some of the stout mixture over the shredded beef.
Layer beef into a warmed/steamed tortilla, add cheese, cabbage, avocado, cilantro, fresh squeezed lime and crema. Enjoy!