Preheat oven to 400 degrees.
Peel beets and cut into large chunks.
Transfer beets into a mixing bowl, add 2 tbsp. of EVOO with salt and pepper, and mix well.
Wrap beets in tin foil and place on baking sheet. Bake for 1 hour. Beets are done cooking when they become soft (you can stick a knife/fork into it easily).
While beets are cooking, toss arugula and onions in a mixing bow, and mix in the dressing.
Lay arugula mixture on a serving tray.
Cut beets into smaller chunks and lay over arugula.
Add tangerines, dates, and walnuts to rest of salad and serve. If using goat cheese, add at this time.