Combine all spices, olive oil, garlic and lime juice in a small bowl.
Pour this mixture into a Sous vide bag.
Add the steak, turning it in the bag several times to thoroughly coat.
Lay the cilantro across the top of the steak, and seal the bag. It’s important to remove as much air as possible. Vacuum sealing is preferred, but not necessary as you can also use the water displacement method. To do this, slowly lower the bag into water, keeping the open top above the surface. The water pressure will force the air out of the bag, allowing you to seal it once removed.
For the peppers and onions
Slice the peppers into strips.
Halve the onions, and cut to similar size as the pepper strips, breaking apart any larger chunks that stick together.
Toss the veggie strips in a large bowl with the olive oil, add to another Sous vide bag, and seal. For this step more than with the steak, vacuum sealing is preferred. If that isn’t an option, you can add a scant 1/2 to 3/4 cup of chicken broth to the veggies, allowing you to use the water displacement method to effectively remove the air.
Submerge both bags in the Instant Pot, close the lid and set for 2 hours.
Just before done, preheat your broiler. Once finished, carefully remove both bags and pat dry.
Using a broiler pan, or similar sheet, cut open the veggies, discarding the broth if used, and spread them evenly over the pan, leaving room for the steak.
Remove the steak from the bag, discard the cilantro, and place next to the veggies.
Broil for approximately 2-4 minutes or until just starting to brown and char, turn the steak, mix the veggies with tongs, and broil for another couple minutes.
Transfer the steak to a cutting board and let rest for 5 minutes, then slice thinly against the grain.
Serve on warm flour tortillas with the peppers and onions, accompanied by avocado slices, and fresh lime wedges for squeezing.