• Add dried tangerine skin in a small bowl and add hot water to cover. Let soak for about 20 minutes, or until the tangerine skin softens. Drain and finely slice. Transfer 2 tablespoons sliced tangerine skin into a bowl, and save the rest in an airtight container in the fridge for next time. If you do not use dried tangerine skin, grate orange skin to make 2 tablespoons orange zest instead.

Prep chicken

• Combine chicken pieces, vegetable oil, and salt in a big bowl. Add the beaten egg. Stir to mix well. Mix well and let marinate for about 15 minutes while preparing other ingredients.

Sauce

• Add the rest of the sauce ingredients to the bowl with the tangerine skin or orange zest. Mix well.

Cook

• Add cornstarch to the marinated chicken. Stir to coat chicken, until it forms an uneven coating with a little dry cornstarch left unattached.
• Heat oil in a heavy duty skillet until hot, until it just starts to smoke. Add chicken all at once and spread out into a single layer in the skillet. Separate chicken pieces with a pair of tongs or chopsticks.
• Cook without touching the chicken until the bottom turns golden, about 3 minutes. Flip to brown the other side, 2 to 3 minutes. Transfer chicken into a big plate and remove the pan from the stove. Let cool for 2 to 3 minutes.
• Place the pan back onto the stove and turn to medium heat. You should still have 1 to 2 tablespoons oil in the pan. Add more oil if the pan is dry. Add green onion and garlic. Cook and stir a few times until it releases its fragrance.
• Stir the sauce again to dissolve the cornstarch completely. Pour into the pan. Stir and cook until it thickens, when you can draw a line on the bottom with a spatula without the sauce running back immediately.
• Add back the chicken pieces. Stir to coat chicken with sauce. Add the rest of the green part of the green onions and garnish with sesame seeds, if you’re using them.
• Transfer to a plate and serve hot over steamed rice.