Heat the oven to 400°F.
Slice off the beet leaves close to the tip of the beet. Discard the beet greens. Scrub the beets thoroughly, then wrap them loosely in aluminum foil.
Transfer the wrapped beets to a baking sheet. Roast for 50-60 minutes. Check the beets every 20 minutes or so. If they are starting to look dry or are scorching on the bottoms, dribble a tablespoon of water over the beets before re-wrapping. Beets are done when a fork or skewer slides easily to the middle of the beet. Small beets will cook more quickly than large beets.
Let the beets cool enough to handle. Hold one of the beets in a paper towel and use the edges of the paper to rub the skin away. The skin should peel away easily; if it doesn't, the beets likely need to cook for a little longer. Peel the remaining beets and then slice them into wedges.
Combine the arugula, beet wedges, farro, shaved fennel, avocado and goat cheese on a large serving platter and drizzle with basil vinaigrette. Sprinkle the pepitas on top and serve immediately.