The night before you plan to cook the steaks, pat dry with paper towels and put on a wire rack set inside a rimmed baking sheet. Season generously with salt and pepper and chill, uncovered, until about an hour before you want to cook your steaks. Pull steaks from the refrigerator and let sit on your counter at room temperature.
Add 1 cup of liquid to the drip tray and preheat Kenyon Grill to high.
Grill the steaks until golden brown, about 5 to 6 minutes, turn over and continue grilling 5 to 6 minutes for medium-rare doneness. Transfer the steak to a cutting board and let rest for 5 minutes. Arrange sliced steaks on a platter and sprinkle with sea salt.
Garlicky Harissa: Place guajillo chiles and chiles de árbol in a large bowl and pour in boiling water to cover. Let soak until softened, 40–45 minutes; drain.
Meanwhile, toast cumin seeds in a dry small skillet over medium heat, swirling the pan often, until fragrant, about 2 minutes. Let cool, then finely grind in a spice mill or with a mortar and pestle.
Drain chiles; transfer to a blender and purée, adding hot water by the tablespoonful as needed until smooth. Strain chile mixture through a fine-mesh sieve; discard solids. Mix in ground cumin, garlic, oil, and vinegar. Season with salt and let sit 15 minutes before serving.