1. Bring a large pot of salted water to a boil. Add the green beans and cook 1 minute. Add the sugar snap peas and cook 1 minute longer. Drain, rinse under cold water and drain again. Cut the sugar snaps across in half and transfer, with the beans, to a large bowl.
2. Add the cucumbers, celery, bell pepper, radishes, lettuce, onion, and blue cheese to the bowl with the green beans.
3. In a separate bowl, whisk the vinegar, mustard, shallots, oil, salt, and pepper; pour over the vegetables and toss well.
To make this even heartier (and suitable as a meatless entrée), add drained, rinsed canned chickpeas.