Mince the scallion and garlic.
Saute 2 slices of chopped bacon with the shallot and garlic. (Bacon can be easily cut directly in the pan using kitchen scissors).
When bacon is crisp, pour off all grease, then add 1/4 cup vinegar and 3/4 cup cold water, 2-3 tablespoons sugar (or to taste).
Thicken the mixture with 1 heaping tablespoon of cornstarch mixed in a tablespoon of cold water. Cook over high heat for 12 minutes or until mixture is thickened.
Pour over the cooked drained green beans; serve.