Haricots verts are slender French green beans. If you can't find them, use regular fresh green beans, but cook them a minute or two longer.
1 gallon water
1 1/2 teaspoons salt, divided
3 pounds haricots verts, trimmed
1/4 cup Champagne vinegar
1/4 cup finely chopped shallots
2 tablespoons Dijon mustard
2 tablespoons honey
1/2 teaspoon freshly ground black pepper
2 1/2 tablespoons extravirgin olive oil
How to Make It
Bring 1 gallon water and 1 teaspoon salt to a boil in a Dutch oven. Add beans to pan; cook 3 minutes or until crisp-tender. Drain and plunge beans into ice water; drain.
Combine remaining 1/2 teaspoon salt, vinegar, and next 4 ingredients (through pepper) in a large bowl, stirring well with a whisk. Slowly drizzle oil into vinegar mixture; stir well with a whisk. Add beans to vinegar mixture; toss to coat.