Bring your steak to room temperature for about 20 minutes. Using a mortar and pestle or molcajete, grind the spices listed to create a blend. Season the steak lightly on both sides. Slice your peppers and onions, set aside.
Preheat a cast iron skillet to medium heat for a few minutes until it's smoking slightly. Add 2 tablespoons of oil onto steak. Cook and sear steak for 6-8 minutes, turning halfway through cooking time. For rare steak internal temperature should read 125-130 degrees, medium 140 degrees. Remove from pan and tent loosely with foil paper for 5 minutes.
In that same cast iron pan, add the poblano, jalapeño and red onion. If you have some spice blend leftover, season the pepper/onion mix lightly. If not, use some more salt and fresh cracked pepper. Saute for 5 to 6 minutes, adding a little more oil if needed. Remove from heat.
Slice the steak thin and against the grain. Toss back into pan with pepper/onion mix. Add the lime juice . Serve with warm tortillas, salsa verde, guacamole and cilantro.
For quicker seasoning of the steak, you can use previously ground spices.