- Preheat oven to 350 degrees
- Rinse the beets well, and trim the stems and roots, leaving about an inch of each. Wrap the beets individually in aluminum foil. Place the foil-wrapped beets on a baking sheet and roast until tender, about 1 hour. Remove from oven and set aside until cool enough to handle.
- Unwrap the beets and slip the skins off. (Wear rubber gloves to prevent your hands from being stained.) Cover and store in the refrigerator until ready to use.
- Cut the beets into ¼-inch dice (about 4 cups), place in serving dish and set aside.
- In a heavy saucepan over medium heat, whisk together the sugar, crystallized ginger, vinegar, orange juice, cornstarch, salt and pepper. Bring to a boil, whisking constantly until the mixture is clear and thickened, about 4-5 minutes. Whisk in the butter and zest, and cook just until butter is melted.
- Remove the pan from the heat, and pour the sauce over the beets. Toss gently, and let cool completely before serving.