1. Cut the beets from the beet greens. If beets are very small, drop them into a pot of boiling, salted water. Cook, uncovered, for 3 to 5 minutes or until crisp-tender. Immediately submerge the cooked beets in cold water. If using larger beets, drop them into a pot of boiling, salted water. Cook, uncovered, for 20 to 30 minutes. Immediately submerge the cooked beets in cold water.

2. In a small mixing bowl, combine the orange juice and mustard and stir to blend. Whisk in the oil, then stir in the shallot and parsley. When the beets are cool enough to handle, remove their skins. Place whole baby beets in the dressing. Toss to coat. If using larger beets, slice or dice beets, then add to the dressing. Toss to coat.

3. Pull the center ribs from the beet greens and discard. Rinse the leaves and pat them dry, then tear into bite-size pieces. Transfer to a large salad bowl. Using a slotted spoon, remove the beets from the dressing and set to one side. Pour the dressing over the greens, sprinkle with salt and pepper, and toss to coat evenly. Place a portion of dressed greens on each of 4 salad plates. Divide the beets among the plates, arranging them on top of the leaves. Sprinkle on the chopped walnuts and feta (if using).