1-1/4 lb. fresh green beans,ends cut
1/4 cup plus 1/4 tsp. salt
1 medium-small shallot, thinly sliced
2 tbsp. tarragon vinegar
1 tbsp. Dijon mustard
1 tbsp. roughly chopped fresh tarragon
1/4 tsp. freshly ground black pepper
1/4 cup extra-virgin olive oil

Add the 1/4 cup salt to 4 quarts of water and bring to a boil in a large saucepan. In a medium mixing bowl, whisk together the shallot, vinegar, mustard, tarragon, the 1/4 tsp. salt, and black pepper. Slowly whisk in the olive oil. Add the beans to the boiling water and cook until tender throughout (4 to 5 minutes) Drain the beans and place in a serving bowl. Toss with all the vinaigrette. Serve immediately.