Place the beets on a sheet tray and roast until fork tender, about an hour. Remove and let cool.
Using a paring knife, peel the beets. Grate the beets and the pears on the largest holes of a box grater. Toss them with the balsamic, olive oil and salt.
Divide the arugula between 4 salad plates, spoon some of the beet-pear mixture onto the arugula and top with the chopped almonds and chives. Serve immediately.