1. Place the oven rack in the top position and set the broiler to high. Place the jalapeños on a sheet of aluminum foil and roast, turning every few minutes until charred evenly (6-9 minutes).
2. Wrap jalapeños in the foil and let sit until cool enough to handle safely (10 minutes).
3. Remove the skin, split the peppers, and remove the seeds. Slice into thin strips and set aside.
4. Place remaining ingredients in a food processor and process until smooth. Transfer to a serving bowl and stir in the sliced jalapeños.
5. Serve warm or chilled.