**Wear rubber gloves when handling beets! Trim beet greens and wash well. Place in 2 1/2 qt saucepan and cover with water. Bring to boil, reduce heat and cook 25-40 minutes (depending on size) until tender. Drain and let cool until you can handle them. Peel beets and cut into slices or wedges. (You can probably use canned beets - just skip this step).
Stir together mustard, vinegar, oil, and tarragon. Pour over beets. Season with salt and pepper. Toss and serve hot or at room temperature.