Preheat the oven to 375 degrees F. Spread enough kosher salt on a baking sheet to create a bed for the beets. Arrange the beets on the salt, then roast
until you can pierce through them easily, 45 to 90 minutes. Cool the beets at room temperature 30 minutes, then peel
and cut into medium dice
. Chill 1 hour.
Meanwhile, toast the pistachios in the oven, about 8 minutes. Pulse in a food processor until just crushed (not too fine).
Whip the goat cheese in the cleaned food processor with the oil and salt and pepper to taste.
Smear some of the goat cheese in the bottom of 6 bowls. Toss the beets with the vinegar, then divide them among the bowls and top them with another dollop of goat cheese. Sprinkle the pistachios over the top and serve.