To make the sauce, in a small bowl, combine soy sauce, sweetener, sesame oil, crushed garlic, and 1/4 teaspoon onion powder. Mix well.
Using a spiral vegetable slicer, cut zucchini into spaghetti-like noodles. (If you don’t have a spiral veggie slicer, peel zucchini into super-thin strips, rotating the zucchini after each strip.) Roughly chop for shorter noodles.
Bring a wok (or large skillet) sprayed with nonstick spray to medium-high heat. Add chicken pieces, and sprinkle with garlic powder and remaining 1/4 teaspoon onion powder. Add frozen veggies, bean sprouts, and mushrooms. Cook and stir for about 5 minutes, until chicken is cooked through and veggies are hot and tender.
Add zucchini noodles and scallions. Cook and stir until hot and slightly softened, about 3 minutes.
Transfer wok contents to a strainer, and thoroughly drain excess liquid.
Return wok to medium-high heat, and return drained mixture to the wok. Add sauce, and cook and stir until sauce is evenly distributed and mostly absorbed, about 2 minutes.
Recipe from Lisa Lillien's Clean and Hungry.