1 teaspoon extra virgin olive oil
20 or so shishito peppers (about 4 or 5 ounces, 1 small basket)
Sprinkle of kosher salt
2 Tbsp balsamic vinegar (optional)
Toss shishito peppers with extra virgin olive oil in a bowl, so the peppers are well coated.
Heat a well seasoned cast iron (or a pan that can take high heat) on high heat. When the pan is hot, add the peppers to the pan in a single layer. Let the peppers sear and blister on one side, then use tongs to turn them over individually to sear on the other side.
Remove to a bowl and sprinkle the shishito peppers with salt.
Make balsamic glaze (Optional):
Add a couple tablespoons of balsamic vinegar* to the pan. Remove from heat, and let bubble until the vinegar reduces to a glaze, which should be very quickly. Pour over the blistered shishito peppers.
*Balsamic vinegar can be syrupy and sweet, or thin and acidic. Use the syrupy kind. If what you have is thin and very acidic, stir with a half teaspoon of sugar or honey before adding to the hot pan.