In a 5- to 6-quart pan, add chicken broth, ginger, garlic, rice vinegar, and soy sauce. Bring to a boil over high heat. Add potstickers or won tons and simmer, uncovered, until hot in center (cut to test), 6 to 8 minutes. Add sliced green onion. Serve in bowls and add Asian (toasted) sesame oil to taste.