In a medium bowl, combine chicken, Shaoxing wine, cornstarch and 1 tablespoon soy sauce. Cover; place into the refrigerator for 30 minutes.
Heat 1 tablespoon canola oil in a large skillet over medium high heat. Working in two batches, add chicken and cook until golden brown, about 6-8 minutes. Transfer to a paper towel-lined plate.
Heat remaining 1 tablespoon canola oil. Add bell peppers and onion. Cook, stirring occasionally, until just tender, about 2 minutes. Stir in chiles, garlic, ginger, and peppercorns until fragrant, about 1-2 minutes.
Stir in chicken, remaining 2 tablespoons soy sauce, vinegar and sugar until well combined, about 1-2 minutes. Stir in peanuts.
Serve immediately, garnished with green onions and sesame seeds, if desired.