Preheat oven to 180 C.
Wrap the beets in aluminum foil and put them on a baking sheet. Put the fennel on a separate baking sheet, cut side up, drizzle with olive oil, and season with salt and pepper.
Roast the beets and fennel in the oven until fork-tender (about 30 minutes for the fennel, and 50 to 60 minutes for the beets).
When cool enough to handle, peel the beets and cut them into thin slices. Cut the fennel into very thin slices.
Meanwhile, spread the pecans on a baking sheet and bake until lightly toasted (about 5 to 8 minutes).
Put the arugula (rocket) in a large bowl; add the beets, fennel, nuts, and optional pear, and gently toss together. Drizzle with the dressing and scatter the figs over the salad.