To the bottom of a large salad bowl, add the vinegar, garlic, salt, pepper, and crushed red pepper. Let rest a few minutes to dissolve the salt. Whisk in first the Dijon-style mustard and then the light sour cream until smooth. Taste and adjust seasonings. At this point, you’ll add the salad ingredients on top, (you can refrigerate it here, covered, for an hour before tossing) toss, garnish, and serve.