Pat the thawed shrimp dry with a paper towel and set aside.
In a medium-sized bowl, whisk together the mayonnaise, chili sauce, rice wine vinegar, and Sriracha sauce. Taste and adjust flavors - add a pinch of salt if needed, add more chili sauce if you want it sweeter, or add more rice wine vinegar if it is too sweet. (Read more about how to balance a sauce here.) Set aside the sauce. 1/2 cup mayonnaise, 2 tablespoons Thai-style sweet red chili sauce, 1/4 teaspoon Sriracha sauce, 2 tablespoons rice wine vinegar
In a shallow dish, whisk the egg whites until frothy. Put the flour and the panko breadcrumbs in two other shallow dishes.
3 large egg whites, 1/2 cup flour, 1 1/2 cup panko bread crumbs
Working in batches, dip the shrimp in the flour, making sure that both sides are well coated. Transfer the shrimp to the egg whites, and then finally coat the shrimp in the panko.
1 pound shrimp
Heat the vegetable oil in a large skillet until smoking. Add the shrimp, cooking for 3 minutes on each side. Transfer to a paper towel-lined plate.
1/2 cup vegetable oil
Toss the shrimp carefully in the prepared sauce. Serve in tortilla shells, topped with red cabbage and cilantro.