The Sauce: In a small bowl mix together the soy sauce, rice vinegar, sesame oil, and gochujang sauce until well blended. Set aside.
The Stir Fry: Heat a 14-inch wok or large cast-iron skillet over high heat. Swirl in 1 Tbs. of the peanut oil, add the ginger, garlic, cabbage, bell pepper, and frozen peas. Using a metal spatula, stir-fry the vegetables for 2 to 3 minutes or until they begin to soften. Transfer the vegetables to a plate.
Swirl in another 1 Tbs. of oil. Add the cooked rice and stir-fry 2 to 3 minutes, breaking up the rice with the spatula until it is heated through.
Clear a spot in the center of the pan. Add the eggs, tossing with a fork and cooking them quickly. Stir the cooked eggs into the rice mixture.
Pour in the sauce and stir to mix. Add the cooked chicken and chopped scallions, sprinkle on the salt and pepper, and stir-fry for 2 minutes or until the mixture is heated through. Serve right away.