The salt-and-pepper heel from the fair isle socks bothered me for a couple of reasons. First of all, the slipped stitches on the side were huge, and this resulted in holes. Secondly, it was a stockinette heel, which caused my gusset to be insubstantial.
So I was trying to think of a way to combine heel stitch (or eye-of-partridge stitch) with this salt-and-pepper coloring pattern but was failing miserably. The slipping of the previous row's stitches always seemed to get in the way, thus rendering one of the yarns on the wrong side of the work.
Then it hit me. Why can't one of the yarns sometimes be on the wrong side of the work? After all, we're doing the heel back-and-forth, not in the round. If I combine the "festive" style of knitting (i.e. slipping the stitches I'm not currently knitting, saving them for the other strand), I actually could do heel stitch.
This technique is a bit mind-boggling, at first, because on the first row of the pattern you are knitting two different strands in opposing directions.
The following will give you eye-of-partridge stitch, with all of the slipped stitches being Color B, and all of the recessed stitches being Color A. Connect Color A ready to start a knit row, and connect Color B ready to start a purl row.
Row 1A, Color A (RS): *k1,sl1*, repeat * to end
Row 1B, Color B (WS): *p1,sl1*, repeat * to end
Row 2, Color A (WS): *sl1,p1*, repeat from * to last 2 sts, sl2
Row 3A, Color A (RS): *sl1,k1*, repeat from * to end
Row 3B, Color B (RS): *k1,sl1*, repeat from * to end
Row 4, Color A (WS): sl2, *p1,sl1*, repeat from * to end
I think rows 3A and 3B could be stranded and done at the same time, but if you do this, be careful you keep the floats loose, otherwise this row will bunch. And always slip purlwise regardless of the side you're on.
Just so you know, I haven't tried this yet, so I have no idea if this will work, or if it will resolve the large gusset stitch issue I was having with the salt-and-pepper heel. I plan on trying this on my commute home. I'll keep you posted.