In a small bowl, combine together the oyster sauce, rice vinegar, sesame oil, and 2 tbsp water in a small bowl.
In a medium mixing bowl, combine the chicken thighs, salt, pepper, and cornstarch. Next, preheat a large skillet to medium-high heat and add 2 tbps vegetable oil. Cook the chicken for about 6 minutes or nearly browned and cooked through.
Next, add in the red onion, pepper, garlic, ginger, Aleppo-crushed peppers, and remaining 2 tbsp of oil. Continue to cook until the vegetables have softened, about 2 minutes.
Add in the corn and toss until tender. Pour in the reserved oyster sauce. Mix and continue to cook until reduced to a glaze. Season with salt and pepper as needed.
Serve stir-fry with rice and chopped parsley or cilantro.