Whisk together the chicken broth, oyster sauce, Shaoxing wine, soy sauce, sugar, and cornstarch in a medium-sized bowl.
Heat 1 teaspoon of oil in a small skillet over medium heat until hot. Add the garlic. Stir fry a few times to release the fragrance.
Stir the sauce mixture again to completely dissolve the cornstarch. Pour it into the pan. Stir immediately until it forms a silky sauce that is thick enough to coat the back of a spoon. Immediately transfer to a clean bowl. Set aside.
Add the ground chicken, cornstarch and ¼ teaspoon of salt in a medium-sized bowl. Stir to mix well.
Heat ½ tablespoon of oil in a medium-sized skillet over medium heat until hot. Add the ground chicken. Cook and chop into smaller pieces, until just cooked through, 3 minutes or so. Transfer the chicken to a plate to cool off.
Beat together the eggs, bean sprouts, onion, green onions, cooled chicken, and white pepper powder in a bowl until well-combined.
Heat 1 to 2 teaspoons of oil in the same small skillet over medium heat until hot. Scoop about ½ cup of the egg mixture into the skillet, use the spatula to shape the egg to make a patty. Cook until golden brown, about 2 minutes per side, and repeat with the remaining egg mixture. Transfer the omelet to a serving plate.
Spoon the sauce over the omelets. Serve hot as a main with extra gravy on the side.
