Put beets into a medium pot, cover with salted water and bring to a boil. 

Reduce heat to medium low, cover and simmer until tender, about 30 minutes; drain well. 

When cool enough to handle, cut into chunks.

Zest oranges then transfer zest to a large bowl; reserve oranges. 

Add lime juice, orange juice, oil, salt and pepper and whisk together. 

Add beets, toss well, cover and set aside at room temperature for 1 hour.

Cut thin slices off top and bottom of a orange and set on a cutting board. 

Slice down along the curve of the fruit, removing all skin and white pith, and cutting all the way to the flesh. 

Working over another bowl, cut along each side of the membranes to release the sections, allowing them to fall into the bowl along with any juice. Repeat with remaining oranges.

To serve, add jicama to the bowl with beets, toss to coat and season with salt and pepper. 

Arrange lettuce on plates then spoon beet mixture over lettuce, top with oranges and serve.