If there is room on the grill, the peppers and corn can be cooked at the same time.Plus: More Vegetable Recipes and Tips
Light a grill. Roast the peppers over a hot fire, turning, until charred all over, about 20 minutes. Transfer to a medium bowl, cover with plastic wrap and let steam for 10 minutes. Peel the peppers and cut them into 1/4-inch strips.
Brush the corn with 1/4 cup of the olive oil and grill over moderately high heat, turning, until charred in spots but still slightly crisp, about 7 minutes. Let cool slightly. Working in a large bowl, cut the kernels from the cobs.
Add the peppers and red onion to the corn. Stir in the lime juice and the remaining 1/4 cup of olive oil. Add the cilantro and toss well. Season with salt and pepper and toss again, then serve.