Toss the diced chicken with 1 tsp soy sauce and 1 tsp cornstarch. Leave it for 10 minutes while you prep the vegetables. The cornstarch coating keeps the small pieces tender when they cook.

Heat 1 tbsp of the oil in a large nonstick skillet over medium-high heat. Add the chicken and stir-fry for 2 to 3 minutes until just cooked through and no longer pink. Move it to a large bowl. In the same pan, cook the onion and mushrooms for 2 minutes until the mushrooms release their moisture and begin to brown. Add them to the bowl and let everything cool for 5 minutes so it does not scramble the eggs.

In a small saucepan, combine the stock, oyster sauce, 1 tbsp soy sauce, and ginger. Bring to a gentle simmer. Stir the cornstarch into the cold water, then whisk it into the pan. Simmer for about 1 minute, stirring, until the gravy turns glossy and coats the back of a spoon. Turn the heat to its lowest setting to keep it warm.

Beat the eggs with the salt, white pepper, and sesame oil until the yolks and whites are fully combined. Pour them over the chicken and vegetables. Add the bean sprouts, scallions, and peas, then fold gently. The mixture should look more like a vegetable-heavy scramble than a runny batter. That ratio is what gives the patties structure.

Wipe the skillet and heat 1 1/2 tbsp oil over medium-high heat until a drop of egg sizzles immediately. Ladle in 1/2 cup (120 ml) of mixture per patty, fitting 2 to 3 at a time without crowding. Fry for about 2 minutes until the edges are golden and lacy and the underside is set. Flip and cook 1 to 1 1/2 minutes more. The centers should feel springy, and the eggs should reach 74°C (165°F). Repeat with the remaining oil and mixture to make 8 patties. Serve 2 patties per person with the hot gravy poured over the top and a sprinkle of scallion greens. Rebecca's Tip: Bean sprouts hold a lot of water, and that water makes patties weep and fall apart. Pat them dry with a clean towel, and rest the cooked patties on a wire rack rather than paper towels so the bottoms stay crisp.