Heat a cast iron skillet over high heat. Add corn kernels in a single layer and char for 4 to 5 minutes, stirring once halfway, until 30 to 40 percent of kernels are browned. At the same time, blister the 2 jalapeños and 1 poblano directly over a gas flame or under the broiler for about 8 minutes total, turning every 2 minutes.

Place the charred peppers in a covered bowl for 5 minutes to steam, then rub off the skins. Dice the poblano into 1/4-inch pieces and dice the jalapeños, removing seeds for less heat.

Combine the charred corn, diced peppers, 1/2 cup diced red onion, 3 tbsp cilantro, 2 tbsp lime juice, 1 tsp salt, and 1/4 tsp black pepper in a large bowl. Fold together gently and taste for seasoning.

Spoon into a serving bowl, squeeze a few extra drops of lime juice over the top, and scatter a pinch of fresh cilantro across the surface.