Preheat oven to 375°. Trim beets, drizzle with oil, and wrap in foil. Roast beets until tender when pierced with a fork, 30 to 45 minutes (time will vary depending on size of beets). Unwrap and let cool.
When beets are cool enough to handle, slip peels off and grate beets on the large holes of a box grater. Toss with vinegar and salt, adding more salt to taste if you like. Serve at room temperature.
Note: Nutritional analysis is per serving.