Season both sides of the steak with salt and then generously coat with the Chile-Spiked Pepper Blend. Rub the seasoning into the meat and let sit out on the counter top while preparing the vegetables. Preheat the grill to 500°F.
Cut the peppers in half and remove the core and seeds. Slice the zucchinis and onion lengthwise into quarters. Toss all of the vegetables in a bowl with a drizzle of olive oil and season with salt.
Add the vegetables to the grill and let cook for about 5 minutes or until you can see they are starting to soften and have nice grill marks. Add the steak to the grill and cook for 5 minutes on the first side.
Turn the vegetables and steak over and cook for another 5 minutes, until the steak is nicely seared and registers an internal temperature of 125°F for medium-rare.
Remove everything from the grill and let the steak rest for about 8 minutes to let the juices redistribute. Slice the steak against the grain into ½-inch-thick slices. Cut the vegetables crosswise into strips. Serve on a board alongside warm flour tortillas, cilantro and salsa verde.