How to Make It
In a large pot, cover the beans with 2 inches of water and bring to a boil. Cover the pot partially and simmer the beans over moderate heat, stirring occasionally, until tender, about 1 hour. Add more water, if necessary, to keep the beans covered. Drain the beans, reserving 1/2 cup of the cooking liquid.
In a small bowl, whisk the vinegar, oil and mustard and season with salt and pepper. Transfer the beans to a large bowl. Add the celery, jalapeño, red chile, the reserved bean cooking liquid and the dressing; toss well. Season with salt and pepper. Let the salad stand for 15 minutes, stirring occasionally. Stir in the basil and mint and serve.