Heat your oven to 300º. Line a baking sheet with parchment paper. In a small bowl mix together the brown sugar, cinnamon, salt and cayenne. In a larger bowl beat the egg white and the vanilla.
Fold the walnut into the egg white mixture and stir to coat. Add the dry ingredients and thoroughly mix.
Spread the coated walnuts on the parchment paper. Place in the oven and roast for 20 minutes. After 20 minutes stir the walnuts and return to the oven to roast for another 15 minutes. Remove from the oven and spread the walnuts onto a plate to cool.
Mince the shallot. Whip the minced shallot into the EVOO, white balsamic vinegar and mustard. Set aside.
Cut the endives in half, cut out the core and peel away the leaves.Shred the romaine lettuce. Julienne the apple into matchstick sized pieces. Combine the endive leaves, apple, romaine, candied walnuts and blue cheese crumbles. Add vinaigrette and toss. Place on a serving dish and sprinkle with minced tarragon leaves.