Wash any dirt off the beets, then individually wrap in aluminum foil.
Place on a baking pan and roast for 45 minutes, until a paring knife inserts easily into the center of the largest of the beets.
Let the beets cool for 10 minutes, or until cool enough to handle with your hands, and peel the skin off.
Cut the beets into bite-sized chunks (I like the pieces about 1" big), and place into a bowl.
Add the lemon zest, lemon juice, thyme leaves, olive oil, salt, and pepper, and stir to combine.
Add the pistachios just before serving, as they will get soggy after an hour or so. Enjoy!
If you expect to have leftovers, hold back some of the pistachios, as they will get soggy when stored for long periods of time. Stir in pistachios right before eating.Leftovers will keep for 4 days.This would be a really great side for my quick Chicken Milanese, or Spatchcock Chicken.