In a bowl, combine chicken, soy sauce and Chinese cooking wine. Marinate in the refrigerator for about 20 to 30 minutes. Drain chicken, discarding liquid.
In a bowl, combine egg whites and cornstarch. Whisk together until well-blended and frothy. Add chicken and mix to fully coat.
In a thick-bottomed, deep pan over medium heat, heat oil. Add chicken pieces one at time to prevent from lumping together. Deep-fry for about 5 to 6 minutes or until golden. With a slotted spoon, remove from heat and drain on wire rack. Cook chicken in batches, DO NOT OVERCROWD pan.
In a wide skillet over medium heat, combine calamansi sauce ingredients: calamansi juice, soy sauce, Chinese cooking wine, sesame oil, brown sugar, garlic, ginger and red chili flakes. Heat, stirring regularly, until sugar is dissolved.
In a bowl, combine cornstarch and water and stir until smooth. Slowly add to calamansi sauce, whisking vigorously to prevent lumps. Continue to for about 1 to 2 minutes or until thickened. remove from heat and add chicken pieces, stirring to fully coat with sauce. Garnish with sesame seeds and green onions. Serve hot.