Wash chicken breast, pat dry, and cut into strips.
In a bowl, whisk together 2 egg whites, cornstarch, 1 teaspoon salt, and 1 teaspoon soy sauce until combined. Add chicken strips and mix well to coat evenly. Refrigerate for at least 30 minutes (raw poultry safety).
Heat 2 tablespoons sesame oil in a wok over medium-high heat.
Once hot, cook the marinated chicken strips until golden brown and cooked through (74°C / 165°F internal temperature), about 8-10 minutes. Remove and set aside.
Press 2 garlic cloves into the sesame oil in the wok and stir for about 30 seconds until fragrant.
Add 2 teaspoons ginger and the 500 g frozen Asian vegetables. Stir and cook for 5 minutes.
Meanwhile, stir peanut butter together with hot water, 1 tablespoon soy sauce, and rice vinegar until smooth.
Return the cooked chicken to the wok and pour in the peanut sauce. Stir to combine and warm through for 1-2 minutes.