Marinate chicken in garlic, ginger, siracha, mirin, salt, and pepper for 2 hours.
Mix the sauce and set it aside.
Coat chicken thigh with flour, then dip the flour coated chicken thigh in beaten eggs. Transfer chicken to panko, pressing panko into both sides. Let the chicken rest for 10 to 15 minutes.
Heat oil in a large skillet on medium – high heat (350-degree oil). Cook chicken in the hot oil for 8 minutes. Remove the chicken to a wire cooling rack. Let the chicken rest and cool. Double fry the chicken for about 2 to 3 minutes. Remove onto paper towels.