Heat oil in a wok over medium heat. Cook chicken, stirring occasionally, for 6-7 minutes or until cooked through. Add garlic, toss to combine, then transfer to a heatproof bowl and set aside. Wipe wok clean, then return to high heat. Add eggs and cook, stirring, for 2 minutes or until just cooked through. Add spring onion, pak choy, cooked noodles and chicken, and sriracha mixture, Cook, tossing, for 2 minutes or until heated through and all ingredients are coated in the sauce. Stir through bean sprouts and divide between serving bowls. Top with fried onions, chilli and extra spring onion, and serve immediately.