Cut chicken breasts into bite-sized pieces and place into a large mixing bowl.
In a separate bowl, mix the sesame oil, red wine vinegar, ground ginger, soy sauce and pepper. Add this mixture to the bowl with the chicken and mix well. Marinate at room temperature for about 15 minutes or in the fridge for 30 minutes or more.
In a small bowl, whisk the egg white and cornstarch together until white and frothy. Add to the marinating chicken and combine well.
Heat 1 tablespoon vegetable oil in a wok or frying pan over medium-high heat. Add about a third of the chicken and stir fry until cooked through and golden brown on all sides (5-7 minutes). Transfer to an oven-safe dish and place in a warm 300 degree oven while the remaining chicken cooks. Repeat until all of the chicken is cooked.
While the chicken finishes cooking, add the lemon juice, soy sauce and sugar to a small pan. While that heats, whisk the cornstarch and water together. Bring the lemon mixture to boil, then add the cornstarch-water mixture. Stir constantly until the sauce is smooth and thickens, about 2 minutes.
Return the chicken to the pan and toss to coat with the sauce.
Sprinkle chicken with toasted sesame seeds. Serve with cooked rice and a steamed vegetable.
Recipe by Food Fun Family at https://foodfunfamily.com/easy-lemon-chicken/