I make this dish in the winter when I want that grilled flavor but am unwilling to brave the cold to light the grill. Getting the pan good and hot and thawing the corn to room temperature is the key to this dish.
Heat a large skillet over high heat. Add the onion, red bell pepper, poblano pepper, and corn to the pan and cook, stirring frequently until everything is browned, about 10 minutes. Add water as infrequently as possible so that the vegetables brown well.