Cut chicken into thin bite-size strips. For sauce, in a small bowl stir together the chicken broth, soy sauce, rice wine or white wine, cornstarch, and sugar. Set aside.
Pour cooking oil into a wok or large skillet. (Add more oil as necessary during cooking.) Preheat over medium-high heat. Stir-fry garlic in hot oil for 15 seconds. Add carrots; stir-fry for 3 minutes. Add mushrooms and, if using, fresh pea pods; stir-fry about 1 minute more or until carrots and pea pods are crisp-tender. Remove the vegetables from the wok.
Add the chicken to the hot wok. Stir-fry for 2 to 3 minutes or until no pink remains. Push the chicken from the center of the wok. Stir sauce. Add the sauce to the center of the wok. Cook and stir until thickened and bubbly.
Return the cooked vegetables to the wok. Add water chestnuts and, if using, thawed pea pods. Stir all ingredients together to coat with sauce. Cook and stir about 1 minute more or until heated through. Serve immediately over hot cooked rice. Makes 4 servings.