Heat oil in deep fryer to 350 F.
To make sauce, place the rice wine vinegar, sugar, fish sauce, sherry, garlic, chili flakes and Sriracha in a sauce pan or pot and bring to a rolling boil. Reduce heat to medium and reduce by half. Lower heat to simmer and add the cornstarch-water mixture. Stir until the sauce thickens, makes about 1/2 cup sauce. Remove from heat and let cool. Once sauce is cool, pour into a bowl and mix in mayo, lime zest and juice. Set aside.
In a bowl, combine egg and milk. In another shallow bowl, combine rice flour, cornstarch and breadcrumbs. Bread the shrimp by first coating with the egg mixture then the breadcrumb mixture, then back again into the egg and finish in the breadcrumbs.
Arrange the coated shrimp on a plate and pop them into the fridge for at least 10-15 minutes to help the breading stick while frying.
When oil is hot, fry shrimp 2-3 minutes or until golden brown. Drain on rack or paper towels.
When all the shrimp have been fried, drop into a large bowl. Spoon sauce over shrimp and stir gently to coat. Serve with lime wedges alongside.