1. Turn broiler to high and place the rack in the top position. Place the poblano pepper on a foil-lined baking sheet and broil, turning once, until charred (5 minutes per side). Wrap pepper in foil and let stand on counter to steam until just cool enough to handle (10 minutes).
2. The pepper skin will now easily slough off. Peel, remove seeds and membrane, and chop.
3. Combine all ingredients in a large bowl and serve.