Combine 1 cup mirin and 1/4 cup tamari in a medium mixing bowl. Add the chicken and stir. Cover and let marinate in the refrigerator for one hour. Then strain the chicken pieces to remove any excess liquid.

Combine 1 cup of gluten free flour with 1 tablespoon of salt in a medium size bowl. Add the chicken pieces and stir to coat thoroughly.

Heat 1/2 inch of oil in a heavy skillet to 350°. When the oil is hot put a layer of chicken pieces in the pan and cook, stirring occasionally for 5 minutes until golden. Remove the pieces to a paper towel to drain. Let the oil come back up to 350° and cook another batch of chicken pieces. Repeat as necessary until all the chicken is cooked.

In a small bowl combine 1/2 tablespoon of cornstarch and water. Mix together well so there are no lumps.

In a one cup measuring cup mix together 1/4 cup each of tamari, mirin and rice vinegar.

Heat a small amount of olive oil in a skillet. When the oil is hot add the garlic and ginger. Let cook for 30 seconds and then add the red chiles. Pour in the liquid mixture and add the 1/4 cup of sugar. Bring this to a strong boil and then stir in the cornstarch slurry. Continue stirring as the sauce boils and thickens.

Add the chicken to the sauce and stir to coat thoroughly. Garnish with green onion slices.