How to Make It
Preheat the oven to 400°. Brush the beets with olive oil. Spread the large beets in one roasting pan and the small ones in another one. Season the beets with salt and add 1/2 inch of water to each pan. Cover the pans with foil and roast until tender, about 25 minutes for the small beets and 35 for the large. Let cool, then peel the beets. Slice the golden beets about 1/4 inch thick and quarter the red beets; keep them separate. Leave the oven on.
Toast the walnuts on a small pie plate for about 5 minutes, or until fragrant. Break the walnuts into pieces, toss them with 1 teaspoon of the walnut oil and season with salt. Leave the oven on.
In a bowl, mix the sherry and balsamic vinegars and a pinch of salt. Whisk in the 1/4 cup of olive oil, then whisk in the remaining 1 teaspoon of walnut oil.
In a large bowl, toss the sliced beets with half of the dressing. Arrange them on 4 plates and season lightly with salt.
Heat a large skillet. Add the beet greens with the water that clings to the leaves and cook over high heat, tossing, until wilted. Drain well and transfer to the large bowl. Add the quartered beets, shallot and remaining dressing and toss well. Mound the wilted greens and beets on the plates.
Set the goat cheese rounds on a small pie plate and bake for about 2 minutes, or until just beginning to melt. Using a spatula, transfer the cheese to the plates, scatter the walnuts on top and serve.