Mix together the sriracha and mayo, adjusting to taste, and set aside.

Lightly pat the prawns dry with a paper towel. Heat up 2-3 inches of oil in a very deep, heavy bottomed pot, over medium high heat, until it reaches 350°F.

When the oil is hot, it’s time to make your batter. In a small bowl, mix together the flours, baking powder, and salt. In another bowl, lightly beat the egg and then pour in the water and 1 tablespoon of oil, mixing slightly. Add the flour mix, all at once. Mix a few times with chopsticks, until loosely combined – lumps are okay.

Set up an assembly line beside your stove: the prawns and your bowl of batter. Have a rack set on a plate on the other side of the pot of oil for your finished prawns.

Test the oil heat by dropping in a bit of batter. It should drop below the surface then float up almost immediately, surrounded by tiny bubbles boiling around the edges.

When the oil is ready, use your hands to dip a prawn, holding it by the tail, into the batter. Gently place into the hot oil and fry, turning occasionally until the batter is golden and crisp, 3-5 minutes. Remove from the oil and drain on your prepared rack. You can cook several prawns at once, just be careful not to crowd the oil and drop the temperature. I wouldn’t cook more than 3 at a time.

Enjoy with the chili mayo sauce, lettuce, mint, green onions, and lime.