Step 1

Add oil to Instant Pot and set to Saute. While it heats, salt and pepper the brisket, then sear in the Instant Pot. Work in batches if necessary and transfer brisket chunks to a plate once each side is browned.

Step 2

In the oil remaining, add the onion and saute, scraping the bottom of the Instant pot as needed. Once the onion has softened, add the broth, a little at first, deglazing the pot and the vinegar. Add the jalapeno, close the garlic packet up and place it on top.

Step 3

Lock the lid in place, seal and set to High Pressure, 55 minutes. Do not use the keep warm function when finished; just turn off the pot and let the pressure naturally release (will take about 30 minutes.)

Step 4

Transfer brisket to a bowl and shred. Remove the garlic from the packet, squeeze out the cloves and add the garlic to the beef. Add a little of the juices from the Instant Pot if the beef seems dry or if it seems wet, drain some of the juices back into the Instant Pot.

Step 5

Strain the broth in the instant pot and add any of the solids to the beef. Shred the beef and toss, taste, and add more salt and/or pepper if desired.

Step 6

Return the broth to the pot, turn the Instant Pot on to Saute and allow the liquid to reduce to about a cup. When finished, defeat the sauce if desired, taste and adjust flavors of the broth by adding more vinegar, salt or pepper as desired; set aside for serving.

Step 7

To roast & prepare the poblanos, simply place, touching each other, on a foil-lined baking sheet. Broil, turning as necessary until skin is blistered. Some charring is ok. Remove from oven, wrap in the foil they were roasted on, and leave for 10 to 15 minutes. Remove the skin, stems, and seeds and slice them in strips.

Step 8

In the meantime saute the onions in two tablespoons oil over medium low heat, stirring as necessary until softened and slightly browned on the edges, about 10 to 12 minutes. If the skillet becomes dry or dark. add a little water.

Step 9

When peppers are finished and cut into strips, and the onions are almost ready, add the poblanos. Taste and add salt and/or pepper before serving.

Step 10

Assemble tacos by filling warmed tortillas (warm in a pan, on a burner or on the grill) with cheese, top with the brisket, then the poblano peppers and onions. Serve with the juice and a small salad from the remaining ingredients.

Step 11

Optional step: Fill tacos and griddle over medium-high heat in a little oil until browned in spots and crisped, turning once.