Using stitch holder
With rs facing I've slip 5 stitches on holder, worked stitches in middle then slip 6 stitches on another holder. Then worked middle stitches now I need to with ws facing slip 5 sts on sts holder onto needle then slip 6 sts from other holder on same needle. Then with rs facing rejoin yarn and k5, k2tog, k4.
It's the shaping off the heel of a sock