Soak the bananas: Prepare a bowl of water, squeeze in the juice of one lime, and drop the peels directly into the water. Submerge the peeled bananas for 3 minutes.
Slice the bananas: Using a vegetable peeler or mandoline, slice the bananas into long, paper-thin ribbons. Aim for uniform thickness.
Deep-fry the bananas: Heat neutral oil in a heavy-bottomed pan to 175°C (350°F). If using pandan leaves, add them now to infuse the oil. Carefully drop the banana strips into the oil one by one to prevent clumping. Fry until they reach a deep golden brown and feel rigid. Remove with a strainer and drain.
Prepare the syrup: In a clean, wide pan over medium heat, combine the sugar and water. Stir continuously until the sugar dissolves and the liquid begins to thicken with heavy bubbles.
Sugar-coat the bananas: Turn off the heat and add the fried banana strips to the pan. Use a spatula to gently toss and lift the chips, ensuring every surface is coated. As the temperature drops, the syrup will transform from a clear liquid into a white, frosted sugar crust.
Cool: Spread the coated chips out in a single layer to cool completely. They will continue to crisp up as they reach room temperature.