Preheat the oven to 300 degrees F, and line several baking sheets with parchment paper. Scrub the beets well with a veggie brush and cut off the tops.
Use a mandolin slicer to slice the beets paper-thin (1/16 inch.) When the beet slices are this thin, there is no need to peel them first. Hold the root end while dragging the beets across the mandolin and watch your finger tips closely.
Place the beet slices in a large bowl and pour the oil and salt over the top. Toss well. (If using red and golden beets, place in separate bowls and divide the oil and salt evenly.) Ready for the secret step? Now let the beets sit in the oil and salt until they release there natural juices, about 15-20 minutes. This is what allows them to retain a better shape and color.
Toss the beets again, then drain off the liquid. Lay the slices out in a single layer on the prepared baking sheets. Bake for 45-60 minutes until crisp, but not brown. Test after 45 minutes and only bake longer if necessary. Remove the beet chips from the oven and cool completely before storing in an air-tight container.
Just one bunch of beets available? 1/4 of the recipe will do it:)