In a mixing bowl, combine the chicken thighs with soy sauce, dark soy sauce, oyster sauce, black pepper, and corn starch. Let marinate for about 10 minutes.

Place a non-stick pan over medium heat and add a splash of oil. Heat until it shimmers.

Add the marinated chicken thighs in a single layer and sauté for 8-10 minutes, turning occasionally.

Stir in the white parts of the scallions and cook for 1-2 minutes. Then add the green parts and cook for another 10-20 seconds.

Remove from heat, transfer to a serving platter, and garnish with remaining scallions or black pepper.