Marinate the Chicken:
In a bowl, combine sliced chicken with soy sauce, minced garlic, minced ginger, salt, and pepper. Let it marinate for at least 15-20 minutes.
Prepare the Vegetables:
In a large skillet or wok, add the marinated chicken and cook over medium-high heat until browned and cooked through. Remove the chicken from the skillet and set it aside.
Stir-Fry Vegetables:
In the same skillet, add the mixed vegetables, sliced onions, sliced bell peppers, broccoli, and snap peas. Stir-fry until the vegetables are tender-crisp.
Make the Sauce:
In a small bowl, mix together soy sauce, rice vinegar, minced garlic, minced ginger, and Sriracha sauce.
Combine Everything:
Add the cooked chicken back to the skillet with the stir-fried vegetables. Pour the sauce over the mixture and toss everything together until well-coated.
Garnish and Serve:
Garnish the chicken stir-fry with chopped green onions and sesame seeds. Serve it as is or over cauliflower rice.