Place Hatch chiles directly on grates of a gas stove; cook over medium heat, flipping with tongs occasionally, until blackened and charred, about 5 minutes. Place blackened chiles in a resealable plastic bag, seal, and cool for 7 to 8 minutes. Remove and discard skins and seeds; cut flesh into 1-inch squares.

Melt butter in a large sauté pan over medium heat. Add onion; cook until translucent, about 5 minutes. Stir in corn, chiles, bouillon granules, and black pepper until well combined. Stir in chicken and crema; simmer until heated through, about 5 minutes.