The poblano (Capsicum annuum) is a mild chili pepper originating in the state of Puebla, Mexico.Dried, it is called ancho or chile ancho, from the Mexican Spanish name ancho (wide) or chile ancho (wide chile).Stuffed fresh and roasted it is popular in chile rellenos poblanos. While poblanos tend to have a mild flavor, occasionally and unpredictably they can have significant heat.Different peppers from the same plant have been reported to vary substantially in heat intensity. The ripened red poblano is significantly hotter and more flavorful than the less ripe, green poblano.hile poblanos tend to have a mild flavor, occasionally and unpredictably they can have significant heat. Different peppers from the same plant have been reported to vary substantially in heat intensity. The ripened red poblano is significantly hotter and more flavorful than the less ripe, green poblano.