Create three sheets of foil, one for every three beets, and large enough the encompass the beets and seal at the top.
Trim the tops and bottoms from each beet and place on a sheet of foil.
For each beet, drizzle olive oil, sprinkle with salt and pepper, and add a sprig of thyme. Then, wrap the foil upward towards the top of each beet and seal completely, yet loosely.
Place in a 400-degree oven and roast until tender, about 60 minutes. Test the beet doneness by poking one with a skewer. The skewer should be able to slide through the beet somewhat easily.
Remove the beets from the oven. Open each beet foil pack and let cool for about 10-15 minutes. Using a paper towel, rub the skins off each beet. Cut the beets into bite-sized pieces (can be larger pieces or smaller pieces, whichever you prefer) and add them to a mixing bowl.
Make the Vinaigrette and Toast the Walnuts
While the beets are roasting, combine all the vinaigrette ingredients in a small bowl and mix to combine.
Also, add the walnuts to a small skillet and heat on medium to toast. They are done as soon as you smell them. Watch them closely; they will burn quickly if left on too long. Remove from the heat and set aside.
Prep the cheese, by crumbling it into a small bowl.
Make the Salad
Add arugula to each salad plate/bowl and top with beets. Drizzle vinaigrette over, add crumbled Roquefort and toasted walnuts. Add some flakes of Maldon sea salt if desired. Enjoy!!