Once the cashew mixture is nearly ready, it's time to roast the jalapeños. Turn a gas burner or grill on medium heat. Roast the peppers one at a time. Place each over the open flame for 1 to 2 minutes, or until the skin becomes blackened and blistered. Rotate and repeat on the other side. Once the pepper is blackened and blistered all over, transfer it to a cutting board and invert a bowl on top of it to trap the heat. Allow it to steam for 10 to 15 minutes (this loosens the skin for easy peeling). Repeat with the remaining peppers. (See
this post for a visual if needed.)