In a salad bowl, whisk together the yogurt, shallots, oil, vinegar, salt, and pepper. Add the cabbage and cilantro (if using), and toss to combine.
Refrigerate for at least 1 hour prior to serving. Toss again just before serving. Store leftovers in an airtight container in the fridge for up to 5 days.
Notes
Flanagan, Shalane & Kopecky, Elyse (2018) Run Fast Cook Fast Eat Slow Rodale Publishing