Marinate the chicken in a mixture of soy sauce, fish sauce, lime juice, ginger, garlic, coriander, white pepper, and turmeric for at least 2 hours or overnight.

Prepare the slaw by mixing cabbage and carrots, then whisk vinegar, sugar, and salt to combine before pouring over the vegetables.

Make the spicy mayo by blending mayonnaise, sriracha, lime juice, honey, and sesame oil until smooth and creamy, then refrigerate.

Prepare the batter by whisking flour, cornstarch, rice flour, and baking powder, then gradually add ice-cold water until just combined.

Heat vegetable oil to 350°F (175°C) and fry the coated chicken thighs until golden brown, about 6-8 minutes.

Assemble the sandwich by placing fried chicken on toasted brioche buns, spreading spicy mayo, and topping with pickled slaw and cilantro.