In a large sauté pan over high heat, combine the oil, onion, and salt and sauté for 2 minutes.
Add the carrots, celery, garlic, rosemary, and red pepper flakes and sauté for 1 more minute.
Add 1/4 cup (60ml) of water and cover the pan. Cook over high heat until the vegetables are just crisp-tender (about 2 minutes). Uncover the pan and turn off the heat.
Stir in the beans, tomatoes, and vinegar, and season with salt to taste.
Toss the beans with the arugula and serve garnished with the chopped parsley.