Marinated Beets with Mint

Bake or boil beets, then cool, peel and trim them. Slice beets into thin half moon slices and place them in a medium sized bowl. Add the remaining ingredients (except the feta) and mix well. Cover tightly and refrigerate at least 12 hours (preferably 24 hours or more). Stir the marinating beets from time to time if possible. Serve cold, topped with crumbled feta if desired. Garnish with sprigs of mint.