Step 1

Roast the poblanos over the flame of a gas burner or under the broiler, turning as needed, until charred all over, about 8 minutes. Transfer to a bowl and cover to steam and loosen the skin. When the poblanos are cool enough to handle, peel off the blackened skins and remove the stems and seeds. Chop the poblanos and set aside.

Step 2

Preheat the oven to 375 degrees F. Butter a 3-quart baking dish. Melt 4 tablespoons butter in a large skillet over medium-high heat. Add the onion and scallions and cook, stirring, until softened and translucent, 5 to 6 minutes. Add the garlic, chili powder and cumin. Stir for about 30 seconds to toast, then add the corn and chopped poblanos. Season with 1 teaspoon salt and a few grinds of pepper. Let cool slightly.

Step 3

Whisk together the chicken broth and egg in a large bowl. Add the white bread, cornbread, cheese, cilantro, vegetable mixture and 1 1/2 teaspoons salt. Toss well to combine.

Step 4

Transfer the mixture to the prepared baking dish and dot with the remaining 2 tablespoons butter. Cover with foil and bake 30 minutes, then uncover and bake until the top is golden and feels firm when pressed, 25 to 30 more minutes. Let rest 10 minutes, then top with chopped cilantro before serving.