Step 1 Prepare the peppers: Cut a small slit along the length of one of the peppers, preferably running along a rib. Cut a small crosswise slit along the top of the lengthwise slit to form a "T" shape. Gently open the slit and remove the seeds. Repeat with all the peppers. (If you omit this step and choose to leave the seeds in the peppers, be sure to at least make a small slit in each pepper to vent the air as the pepper fries; otherwise, the peppers will "pop" as they fry.)
Step 2 To make the batter, sift the flour with the cornstarch. In a medium bowl, combine the ice water with a beaten egg. Add the sifted flour to the egg mixture, using a pair of thick chopsticks or a whisk. Cut the mixture with a few coarse strokes to combine; do not stir or beat too much, as the mixture should have some small lumps. Check the consistency of the batter; if it is too liquid, add a couple of extra tablespoons of cornstarch to thicken.
Step 3Place enough oil in the pot to come up the sides 2 to 3 inches. Heat the oil over medium-high heat until a thermometer inserted reads 325 degrees.
Step 4Working in batches, pick up the stem of a pepper with your hand, dip the pepper into the batter, and gently drop it into the hot oil. You can fry 4 to 5 peppers at a time in the oil, as they are small.
Step 5Fry the peppers on all sides until the batter is crisp, 1 to 2 minutes total cooking time. Remove with a slotted spoon and drain them on paper towels. Repeat until you've fried all the peppers, checking the oil temperature before frying each batch.
Step 6Arrange the peppers nicely on a plate. Serve immediately with salt or heated dipping sauce.