For Beet Vinaigrette:
Bring vinegar, sugar, beet and shallots to a boil and simmer until the sugar melts (about 1 minute).
Remove from the heat and add olive oil, season with salt and cracked pepper.
Toss beets with the vinaigrette along with salt and pepper, to taste. Let sit while you prepare the plates.
Spread a circle of cheese onto the center of each plate with the back of a spoon. Add watercress and pistachios to the beets and place on top of the circle of cheese.
Once each salad is plated, finish by drizzling vinaigrette around the perimeter of the plate and sprinkle each salad with toasted pistachios.