Ingredients

• 5 tablespoons unsalted butter, softened
• 3 tablespoons finely chopped shallots
• 3 tablespoons finely chopped flat-leaf parsley
• 2 teaspoons finely chopped tarragon
• 1 1/2 teaspoons grated lemon zest
• 1 tablespoon fresh lemon juice
• 2 lb haricots verts or other green beans, trimmed

Instructions

1. Stir together all ingredients except haricots verts with 3/4 teaspoon salt and 1/4 teaspoon pepper in a large bowl until combined well.
2. Cook beans in a large pot of boiling salted water (1 tablespoon salt for 6 quarts water), uncovered, until crisp-tender, about 6 minutes, then drain. Toss with herb butter.
3. Herb butter can be made ahead and chilled, covered, 3 days or frozen, rolled into a cylinder in plastic wrap and kept in a sealed bag, 1 week. Haricots verts can be trimmed 1 day ahead and chilled in a sealed bag lined with paper towels.