Make the dressing by combining the lime juice, hot sauce, and sea salt in a small glass jar, seal with a lid, and shake well. Set dressing aside to allow the flavors time to mingle.
Heat a grill pan over medium-high heat.
Grill corn and poblano, turning occasionally, until corn is charred deeply browned in spots and poblano is blackened in spots and crisp-tender, 10–12 minutes for corn and 8–10 minutes for poblano. Transfer the corn cobs to a cutting board and let them cool slightly.
Place the charred chile in a ziplock bag and seal, and set aside for 10 minutes. Peel off the charred skin from the poblano, remove the stem and seeds, and dice.
Make the salad by cutting the kernels from the cobs into a small serving bowl, adding the poblano, green onion, and the butter, and mixing until evenly coated.
Add the well-shaken lime dressing and stir to combine. Top with fresh cilantro and freshly cracked black pepper, to taste.