1. Preheat oven to 425°. Wrap beets in foil and place on rimmed baking sheet; bake 50-60 minutes. Let cool; peel and cut into wedges. (If using canned beets, cut into wedges and go to step 2.)
2. Cover farro with water and soak 30 minutes; drain. In a saucepan, combine farro, 3 cups water, and 1/4 teaspoon salt; boil. Reduce heat and simmer 15-20 minutes; drain.
3. In a bowl, whisk together vinegar, oil, mustard, sugar, pepper, and remaining 1/4 teaspoon salt. Toss with remaining salad ingredients, arranging beets on top.