Tutorial: Buttonhole wheel cup

This week’s TAST challenge is the buttonhole wheel cup — a lucky accidental invention by SharonB of Pin Tangle. (I’m sure she won’t take credit, though. As always, she says, “I am sure I just re-invented the stitch and somewhere another person has had the same thoughts.”) She has put this stitch to work in an especially lovely way in the piece shown here. Add the stitch to your repertoire: see the tute.