How to Make It
In a deep fryer or Dutch oven fitted with a candy thermometer, heat oil to 350°F. Line a plate with several layers of paper towels and set next to the fryer.
In a large bowl, combine mayonnaise, chili sauce, Sriracha, and 1/2 tsp. salt. Set aside.
In a medium-sized bowl, pour buttermilk over shrimp. Toss to coat. In a shallow bowl, use a fork to combine cornstarch, flour, and remaining 1 tsp. salt. Working with 5 to 7 shrimp at a time, lift shrimp out of buttermilk, allowing the excess to drip off, and transfer the shrimp to the cornstarch-and-flour mixture. Turn the shrimp in the flour to coat. Use a slotted spoon to gently lower shrimp into hot oil. Fry for 5 minutes, flipping the shrimp once halfway through cooking. Remove shrimp to paper towel-lined plate. Repeat with remaining shrimp.
Once fried shrimp have cooled slightly, gently toss them in the prepared sauce. Lift them out of the sauce, allowing the excess to fall off, and transfer to a serving platter. Garnish with fresh chives and serve immediately.