Beat egg whites with 4 teaspoons of cornstarch in a large bowl. Add chicken strips, turning to coat. Cover, and refrigerate for 15 minutes. Heat oil in a wok or large skillet until hot. Swirl to coat the pan. Carefully add chicken, and stir-fry quickly until about golden, about 2 to 4 minutes. Using a slotted spoon, transfer chicken to a paper towel to drain. Drain the pan, reserving 1 tablespoon of the oil. Return pan to heat and add the garlic, pepper, and onion. Stir-fry until onion begins to soften, about 1 to 2 minutes. Add sugar, broth, juice and zest from lemon, cayenne pepper sauce and wine. In a small bowl, combine the remaining cornstarch and water, stirring to dissolve. Stir cornstarch mixture into the pan, and stir sauce until it thickens. Add chicken, cooking a few minutes or until chicken is completely heated through.