In a large, heavy bottom saucepan heat 3 inches of oil to 350º-360ºF. While oil is heating prepare tempura batter and sesame chicken sauce.
In a large bowl, mix all ingredients for tempura batter together until just combined. Add chicken and coat chicken on all sides.
In a separate bowl mix soy sauce, rice vinegar, brown sugar, corn starch, water, 2 teaspoon sesame oil, and sesame seeds until combined.
Fry chicken in batches to not overcrowd pan. Cook chicken for approximately 7 minutes until a nice golden brown color. Drain on cooling rack.
Once chicken is cooked, in a wok or large skillet over medium high heat, add 2 teaspoon sesame oil, minced garlic, and crushed red pepper. Cook for 30 seconds being careful not to burn. Pour in the sauce and stir as it thickens. This does not take long! Turn off heat and dump in chicken and toss to coat.
Garnish with sesame seeds and scallions and enjoy. Yum!