1. With Bella Spiralizer on linguine setting, spiralize sweet potatoes into long strands, trimming with clean kitchen sheers as needed. Whisk together oyster sauce, soy sauce, 1 tbsp water, hot sauce, vinegar, sesame oil and sugar; set aside.
2. Heat 1 tbsp vegetable oil in wok or large skillet set over high heat; stir-fry bok choy for about 3 minutes or tender-crisp. Transfer to plate. Heat remaining vegetable oil; stir-fry onion, garlic and ginger for 1 minute. Add sweet potato noodles; stir-fry for about 1 minute or until noodles start to soften.
3. Stir in reserved sauce; return bok choy to pan. Cook for about 1 minute or until sweet potato noodles are well coated and just tender. Season with salt and pepper. Sprinkle with green onions.

Tip: Garnish with sesame seeds if desired.