Char poblano peppers over open flame or under broiler until blackened on all sides. Place in bowl and cover with plastic wrap. Allow to steam for about 10 minutes. Run peppers under cool water rinsing away blackened skin. Remove stem and seeds. Dice.
Cook diced onion and poblano pepper in olive oil until tender. Add cooked chicken, broth, corn and seasonings. Bring to gentle simmer until heated through. Adjust salt & pepper to taste.
Serve with diced avocado, fresh cilantro and sour cream.