Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
                        ***DRESSING***
   3      tablespoons   white-wine vinegar
   2      tablespoons   rice vinegar
   2      teaspoons     soy sauce
   1                    garlic clove -- minced
   1      piece         fresh gingerroot -- peeled and minced
                        -- (1-inch)
   2      teaspoons     asian sesame oil
     1/3  cup           canola oil -- or vegetable oil
                        ***SALAD***
   1      tablespoon    sesame seeds
   2      pounds        green beans -- trimmed
   2                    scallions -- chopped fine

Preparation:

In a small bowl, whisk together vinegars, soy sauce, garlic, gingerroot, and sesame oil. Add canola or vegetable oil in a stream, whisking, and whisk until emulsified. Season dressing with salt and pepper. In a small dry skillet toast sesame seeds over moderate heat, stirring, until golden and transfer to a small bowl. In a large saucepan of boiling salted water, cook beans until crisp-tender, about 4 minutes. Transfer beans to a colander and rinse under cold water. Drain beans well. In a large bowl, combine beans, scallions, sesame seeds, and dressing and toss well. Serve salad chilled or at room temperature.