1In a large bowl, layer the beans, onion and green pepper. Set aside.
2In a small saucepan, mix the vinegar, sugar, oil, mustard, tarragon and cilantro. Cook and stir over medium heat until sugar dissolves. Remove from heat and pour over bean mixture. Stir until all ingredients are coated. This is best if it is left to marinate for a few hours in the refrigerator, and stirred occasionally.