Whisk together thoroughly the egg and cornstarch. Add pieces of chicken, turning to coat evenly. In wok or deep-fat fryer, heat 2 inches of oil to 350F. Fry chicken, a few pieces at a time until lightly browned and just cooked through. Drain on paper towels. Combine sauce ingredients, mixing well. Set aside. (The chicken may be fried the first time up to one hour in advance; the sauce can be combined several days in advance and kept covered in the refrigerator.) In frying pan, heat 1 tbs of oil until hot. Add chili peppers and cook until dark red. Add scallions and stir-fry about one minute. Add garlic and ginger, cooking briefly, but do not brown. Remove from heat. Reheat deep oil to 400F. Return chicken to oil, in batches, and cook until crisp and golden brown. Drain on paper towels. Re-stir sauce and add to frying pan with onions and peppers. Cook, stirring until thickened and bubbly. Add chicken and cook, stirring, until well coated and heated through.