Meanwhile, combine chicken, green onions, and 1 cup cheese.Return oven rack to middle level and turn oven to 425 F. Broil vegetables until browned, rotating tray often, about 12 minutes.
Add a pinch of salt and transfer to a rimmed baking sheet. Toss poblanos, jalapeño, yellow onion, garlic, and tomatillos in oil. Heat broiler and move oven rack to top level.In a small bowl, combine juice of half of one lime and sliced red onion with a pinch of salt.
