Wash chicken and cut into 2cm (3/4 inch) cubes. Mix thoroughly with the minced ginger and scallion, then add the Seasoning A ingredients and marinate for 15 minutes. Mix Seasoning B ingredients and set aside. Heat the wok until smoking, add the oil and when very hot deep fry the chicken pieces for 1 1/2 minutes, until golden. Drain chicken pieces, discard most of the oil. Reheat the wok and stir-fry the chillies and crumpled tangerine peel until they darken. Add chicken pieces and stir. Add Seasoning B and the Thickening sauce and stir-fry until the seasoning coats the chicken. Serve.