Cut the eggplant into ½-inch thick slices, then cut the slices into ½-inch strips. Place the cut eggplant into a large bowl of ice water, put a plate on top of the eggplant to weigh it down, then refrigerate for 2 hours. Drain the eggplant pieces from the water but don’t dry them.
Combine the rice flour with the lime zest, garlic powder, and salt. Toss the damp eggplant in the flour mixture.
Heat 2 inches of oil in a Dutch oven or other large, sturdy pot, to 325 degrees. Fry the eggplant in batches until golden brown, about 4 minutes. Transfer the eggplant to a plate lined with paper towels and sprinkle with salt. Serve with the dipping sauce.
Spicy Thai Dipping Sauce
Combine all ingredients in a small saucepan and heat, stirring, until warm and smooth. Put in a small serving bowl and serve with the eggplant fries.