- 7 large eggs, divided
- 1 1/2 tablespoons tarragon vinegar
- 3/4 teaspoon Dijon mustard
- Salt
- Freshly ground black pepper
- 1/4 cup grapeseed oil or vegetable oil
- 1/4 cup extra-virgin olive oil
- 1/3 cup packed tarragon leaves
- 1 lb haricots verts, trimmed
- 1 1/2 teaspoons distilled white vinegar
- 1/3 cup shelled roasted pistachios, coarsely chopped
- Generously cover 1 egg with cold water in a saucepan. Bring to a boil, then simmer, uncovered, 3 minutes. Transfer with a slotted spoon to an ice bath and let stand 5 minutes. Peel egg and set aside.
- Blend tarragon vinegar, mustard, 3/4 teaspoon salt, and 1/4 teaspoon pepper in a blender. With motor running, slowly add oils and blend until emulsified. Add reserved egg and tarragon; purée until dressing is smooth and green. Set aside.
- Cook haricots verts in well-salted boiling water, uncovered, until just tender, 4-8 minutes. Transfer with a slotted spoon to an ice bath, then drain and pat dry. Toss with 1/2 cup vinaigrette.
- Bring 1 1/2 inches water and white vinegar to a boil in a 12-inch skillet. Break 1 egg into a cup and slide into water. Repeat with remaining eggs, spacing them evenly. Poach at a bare simmer until whites are firm but yolks are still runny, 2-4 minutes. Transfer with a slotted spoon to paper towels to drain. Season with salt and pepper.
- Serve haricots verts sprinkled with pistachios and topped with eggs. Drizzle with some of remaining vinaigrette.