Parboil the green beans

Bring a large pot of lightly salted water to a boil. Add the beans and cook for 2 minutes. Drain. Place under cold running cold water to halt the cooking. Pat the beans dry.

Make the sauce

In a small bowl, combine the broth, soy sauce, vinegar, cornstarch, and sugar and stir to dissolve the cornstarch.

Stir-fry the beans

Heat a wok or large frying pan over high heat until hot and add the oil. Add the pork and stir-fry until no longer pink, about 2 minutes. Add the ginger, garlic, green onion, and chile and stir-fry for about 10 seconds until fragrant. Stir in the green beans. Give the sauce a quick stir, then add to the pan and stir-fry until the beans are heated through and the sauce thickens, about 1 minute. Serve with the steamed rice, if using.