Poach the beets. Place sliced beets in a medium sized pot with a tight-fitting lid. Add the red wine vinegar, salt, and black pepper, then enough water to barely cover the beets. Bring to a boil, reduce heat, and cover. Simmer beets, covered for 45 minutes to an hour until a fork easily pokes through.
While the beets are poaching, mix together the yogurt sauce. Serve the beets with some of the poaching liquid and top with yogurt or drain the beets and toss with yogurt for a brilliant pink side dish.