2 tablespoons Moutarde de Dijon
1 cup walnuts
3 lb. Romano beans or green beans, trimmed
3 Tbsp. red wine vinegar
1 garlic clove, finely grated
2 Tbsp. extra-virgin olive oil, plus more for drizzling
¾ cup very coarsely chopped parsley
Freshly ground black pepper
Preheat oven to 350°. Toast walnuts on a rimmed baking sheet, tossing once, until golden brown, 8–10 minutes. Let cool, then coarsely chop.
Cook Romano beans in a large pot of boiling salted water until bright green and tender, 8–10 minutes. Using a slotted spoon, transfer to a bowl of ice water and let cool. Drain and pat dry. Meanwhile, mix vinegar, mustard, garlic, and 2 Tbsp. oil in a large bowl to combine. Let sit 10 minutes for flavors to come together.
Add walnuts and Romano beans to dressing. Finely zest lemon over beans and add parsley. Season with salt and lots of pepper and toss to coat. Transfer to a platter and drizzle with more oil.
Recipe credits: Ignacio Mattos / Photo credits: Michael Graydon