Step 1

In a bowl, combine all of the for the sauce ingredients and whisk to combine. Set aside.

Step 2

Trim excess fat from brisket and cut into 3 even large chunks. Season with kosher salt and pepper on all sides.

Step 3

Set Instant Pot to the "sauté" function. Once it is hot, add 2 tablespoons of olive oil and sear the brisket in batches, so as to not overcrowd the IP until a golden brown crust has formed on all sides, about 3 minutes per side. Transfer browned brisket to a plate. Continue searing brisket until all pieces browned.

Step 4

Once all the brisket is browned, turn Instant Pot to "off". Pour the sauce into the Instant Pot and nestle the brisket into the sauce. Lock lid onto the Instant Pot, making sure the vent is sealed. Press the "manual" and then set the time to 60 minutes. Walk away from the IP and let it do it's thing! ( Note: If your IP doesn't have a manual button, set it to 'high pressure').

Step 5

When the cook time is complete, release the pressure manually by carefully turning the valve. When all of the pressure has been released, remove the lid and transfer brisket to a rimmed baking sheet (do not discard the remaining liquid in the IP). Using two forks, shred the brisket.

Step 6

Ladle about 3/4 cup of the remaining juice from the Instant Pot over the meat and toss to coat. The brisket will start to absorb the liquid. Add an additional 3/4 cup of liquid to the meat and toss to coat one last time.

Step 7

With the remaining liquid still in the Instant Pot, set the Instant Pot to the "sauté" function and bring to a rapid boil. Cook, stirring occasionally, until the gravy thickens and reduces, 8 to 10 minutes. Remove from heat and use for serving.

Step 8

During the last 10 minutes of the brisket cook time, sauté the peppers and onions. Heat a skillet, preferably cast iron, over medium high heat with olive oil. Once hot, add the poblano peppers and onions. Saute, tossing occasionally, until the vegetables are slightly tender, about 7 minutes.

Step 9

Assemble tacos by filling warmed tortillas with the brisket, poblano peppers and onions. Top with freshly chopped cilantro and a slice of lime and serve with a side of the gravy and a wedge of lime.