I sourced some bamboo worktops from portable workbenches.  After sanding these down and cut them into pieces, I assembled them into two chopping boards.  Trying to minimise the pre-existing glue lines, replacing those with a food safe variety.  I soaked them for half an hour in Danish Oil, and left to cure for one week.  After which I added a few top coats of Tung Oil and again left to cure.