Cold Marinated Green Bean Salad

Bring a pot of salted water to a boil. Add green beans and cook until crisp tender, about 7 minutes. Drain and rinse with cold water (or submerge in a bowl of ice water) to stop the cooking process. Transfer to a bowl.

While the beans are cooling, combine dill, onion, vinegar, Dijon mustard, salt, and pepper in a medium bowl. Slowly add oil, whisking to combine. Let stand for 10 minutes.

Pour dressing over the green beans, tossing gently to coat. Marinate in the refrigerator for at least 2 hours or up to 3 days before serving.