The day before or the day of the grilling - Roast Salsa Verde veggies under a broiler at 500 F or over high heat on the grill until charred. Blend olive oil, salt, pepper, and veggies in a food processor until smooth. (reserve extra jalapenos and tomatillos to adjust heat level of salsa)
Grill steak over high hight for 2-3 minutes on each side until medium rare. Desired internal temperature of 130F.
Use flank steak or flat iron chuck steak if you cannot find skirt steak