For the sauce:
½ cup mayonnaise
2 tablespoons Dijon mustard
1 teaspoon Sriracha
For the peppers:
2 dry pints shishito or padron peppers
1 tablespoon olive oil
Coarse kosher salt or sea salt
If you’re already grilling something, you can follow the same method for cooking the peppers on the grill. If you have leftover dipping sauce, it keeps well, covered in the refrigerator, for several days.
To make the sauce, mix together all the ingredients in a small bowl. Adjust as desired with more Dijon or Sriracha to taste.
To make the peppers, heat a cast iron skillet under the broiler until it’s warm. Combine the peppers and oil in a large bowl. Season with salt and toss to coat.
Pour the peppers into the hot skillet. Cook for 2-3 minutes without stirring, then stir every minute or so for another 2-3 minutes. The peppers should be blistered and darkened all over. Transfer to a serving platter, and sprinkle with additional salt if desired. Serve immediately, with dipping sauce on the side.