Situation You cut a spicy/charif item of one gender on a cutting board (whether wood or plastic), and then cut the opposite-gender spicy/charif food on that same cutting board.
Status Generally, the board and the knife and whichever food was cut second becomes non-kosher. Consult a rabbi for exceptions.
What To Do If you can sand off the surface to below the level of any knife cuts, the board might be kosher. Consult a rabbi.