Marinate the chicken: Mix the marinade ingredients in a small bowl. Add the chicken pieces, making sure every piece is well-coated. Let the chicken marinate for at least 10-30 minutes, or up to an hour for a more intense flavor.

Prepare the stir-fry sauce: In another small bowl, combine the sauce ingredients and set aside.

Stir-fry the chicken: Heat a wok or large skillet over high heat until very hot. Add a small amount of cooking oil. Add the marinated chicken chunks in a single layer without crowding the pan. Stir-fry the chicken constantly until golden brown. This should take about 5-7 minutes until the chicken is cooked through and no longer pink inside.

Stir-fry the green beans: Heat a large skillet or pan over medium-high heat. Add the rest of the cooking oil. Once hot, add the minced garlic and stir fry until fragrant. Add the green beans and continue to stir fry for 2-3 minutes until tender-crisp. Pour the water into the wok, cover it, and let the green beans steam for an additional 2 minutes.

Combine and finish: Return the chicken chunks to the green bean. Pour in the stir-fry sauce mixture and toss everything together. Let it cook for another 1-2 minutes until everything is well-coated and heated through.

Serve: Serve the string bean chicken over white rice, brown rice, or cauliflower rice.