Hi @jak01. This is a difficult one. At first I figured I would just try to get rid of the two pawns. You can't checkmate with a king and a bishop so that seems the easiest solution to me. However, I can't figure out a guaranteed way to do that. Then I figured that if the black king stayed at b8 it would essentially force a draw. Here is my solution:

...f3
gxf3, gxf3
Bxf3 Kb8

From here, the king will either move to a8 or c8 depending on the position of the bishop. White king will never be able to take the pawn at a7 because the king will block approach by b7 and the pawn blocks approach by b6. White bishop is the wrong color to take the pawn as well.
The white pawn at a6 limits the black king's movement and I can't find a single configuration of white's pieces that will actually checkmate at this point.