I started with this...
I removed the only pane of glass and gave the frame a good sanding and cleaning. I then took the measurements of the frame and build a simple box with 1 x 4 pine with those measurements.
I then added another piece of pine to create a shelf. I measured it to line up with the cross piece of the window frame.
I then attached the window frame to the box with wood screws.
I added a beadboard backing.
I stained the back with dark walnut Minwax stain and painted the frame with homemade chalk paint in a green color. I sanded it and applied Minwax paste wax.
Now I have storage and a display shelf for my bread boards.