Season the Steak: Sprinkle the steak with 1 teaspoon of kosher salt and a generous amount of freshly ground black pepper. Separate the cilantro stems from the leaves. Finely chop enough stems to make ½ cup.
Prepare the Marinade: In a bowl large enough to hold the steak, mix the chopped cilantro stems, honey, lime zest, lime juice, soy sauce, minced jalapeños, and olive oil. Stir until combined.
Marinate the Steak: Add the steak to the bowl, turning it over several times to ensure it is evenly coated with the marinade. Cover the bowl with plastic wrap or a lid and refrigerate for at least 2 hours or up to 24 hours for maximum flavor infusion.
Preheat the Heat Source: Preheat your grill or broiler to high. If using a broiler, move the oven rack to the top-third position for optimal heat exposure.
Cook the Steak: For grilling, place the steak directly over the heat and cook on both sides until it is nicely browned and reaches your preferred level of doneness. If broiling, arrange the steak on a broiler pan and cook until the surface is caramelized and cooked through, flipping halfway through. Refer to standard steak cooking guidelines for timing.
Rest and Slice: Transfer the steak to a cutting board and let it rest for about 5–10 minutes to allow the juices to settle. Then, slice the steak thinly, cutting against the grain for the most tender bites.
Garnish and Serve: Top the sliced steak with fresh cilantro leaves and, if desired, additional sliced jalapeños for extra heat. Adjust seasoning with more salt if needed and serve immediately.