Preheat oven to 375°.
Beat egg white and mix well with kosher salt.
Place beets in a baking pan and cover in moist salt mixture, bake 1 hour.
Remove salt crust and let cool (you can omit steps 1-4 and use boiled beets).
Grate beets into a mixing bowl using a box grater.
Mix beets with, Dijon, capers, lemon zest & caper juice to taste
Using a ring mold, spoon 1 cup of beets onto a plate.
Add garnish of radish, chèvre and roquette.
Wrap endive around the outside of the ring mold.
Carefully remove ring mold, ensuring the endive stays wrapped around the beet tartare.