In a medium bowl, combine the pork, 2 tablespoons soy sauce, the garlic, ginger and cornstarch.
In a pot of boiling water, cook the noodles according to package directions; drain. Rinse with cold water until cool.
Meanwhile, in a wok, heat the oil over high heat. Add the pork and stir-fry for 1 minute. Lower the heat to medium and add 1 cup water, the green beans and remaining 2 tablespoons soy sauce. Simmer until the sauce has thickened slightly, 3 to 5 minutes.
Add the carrots and noodles to the wok and toss until heated through, about 2 minutes. Divide among 4 plates and sprinkle cashews on top.