Brush beets with 1-ounce of olive oil and sprinkle with half of salt. Place in a preheated 275 degree oven and bake for 2 hours or until beets are tender. Remove skin from beets and slice into 1/4-inch thick discs and set aside. Layer beets on plate alternating colors. Top with watercress and crumbled blue cheese. Drizzle with remaining olive oil, zest and orange juice. Sprinkle with remaining sea salt and serve.