In a small bowl, whisk together the soy sauce, orange juice, rice wine vinegar, light brown sugar, sesame oil, red pepper flakes and cornstarch. Reserve.

Set a wok over medium-high heat and coat with 1 tablespoon of peanut oil. When the oil shimmers, add about half of the chicken thigh pieces. Stir-fry until the chicken is fully cooked through, about 3 to 4 minutes. Transfer to a plate and repeat the process with the remaining chicken thighs.

Add enough peanut oil to the hot wok to coat the bottom. Add the garlic, ginger, green onions, and red pepper flakes, to taste, and saute until fragrant, about 1 minute. Add chicken back to the pan along with the broccoli florets and stir to warm through. Pour in the reserved sauce and stir until the sauce is thickened and bubbly, about 45 seconds. Transfer to a serving bowl and serve.