Preheat broiler and place poblano on a baking sheet. Broil as close to the heat source as possible, about 2 minutes on each side, until charred all over. Transfer to a small bowl, cover toightly with plastic wrap and let stand fror 5 minutes. Remove the skin from the poblano with a paper towek. Discard the stem and seeds. Cut into a 1/4-inch dice. Transfer to a medium bowl, and set aside. 

Broil the tomatillos on a baking sheet for 3 minutes, turning once, until lightly golden-browned. Transfer to the bowl of a food processor and purée. Combine the tomatillo purée with the diced poblano. Fold in the minced onion, garlic, cilantro, lime juice, and half of the avocado. Mash everything with a fork. Add the rest of the diced avocado and mash lightly. Season to taste with salt and pepper, and serve right away.