Materials: sock weight yarn (fingering), 100 grams.

Samples done in Opal sockweight and Regia sockweight

Needles: 2 #1 circular needles, or size needed to obtain gauge.

(If you wish to use DPNs, I recommend using 5)

Gauge - 8 stitches per inch.

The instep stitches stay on one needle throughout, and the heel stitches on the other.

Cast on 80 stitches loosely. Move half the stitches to the second needle. Join, being careful not to twist the cast-on row. Work 13 rounds of K3, p2 ribbing. Then work one round of *K1, p4; rep from * around.

Pattern rounds:
Rnd 1: *K4, p1; rep from * around.
Rnd 2: *K3, p2; rep from * around.
Rnd 3: *K2, p3; rep from * around.
Rnd 4: *K1, p4; rep from * around.

Repeat the 4 pattern rounds until your leg is long enough. I suggest 12 pattern repeats for about five inches. End on a K1, p4 row.

When you are satisfied with the length of the leg, begin your heel flap on the 40 stitches on one needle while the other waits.

Row 1:
Sl 1 purlwise, * K1, Sl 1 knitwise; repeat from * until last stitch, K1.
Row 2:
Sl 1 purlwise, p38, K1

Repeat above 2 rows 20 times, for a total of 40 rows.

Or if you prefer an eye of partridge style heel flap:
Row 1:
Sl 1 purlwise, * K1, Sl 1 knitwise; repeat from * until last stitch, K1.
Row 2:
Sl 1 purlwise, p38, K1
Row 3:
Sl 2 purlwise, * K1, Sl 1 knitwise; repeat from * until last 2 stitches, K2.
Row 4:
Sl 1 purlwise, p38, K1

Repeat the above four rows 10 times, for a total of 40 rows

Turning the heel:
Row 1:sl1, knit 21, ssk, k1, turn
Row 2: sl1, p5, p2tog, p1, turn
Row 3: sl1, k6, ssk, k1, turn
Row 4: sl1, p7, p2tog, p1, turn
Row 5: s1, k8, ssk, k1, turn
Row 6: sl1, p9, p2tog, p1, turn
Row 7: sl1, k10, ssk, k1, turn
Row 8: sl1, p11, p2tog, p1, turn
Row 9: sl1, k12, ssk, k1, turn
Row 10: sl1, p13, p2tog, p1, turn
Row 12: sl1, k14, ssk, k1, turn
Row 13: sl1, p15, p2tog, p1, turn
Row 14: sl1, k16, ssk, k1, turn
Row 15: sl1, p17, p2tog, p1, turn
Row 16: sl1, k18, ssk, k1, turn
Row 17: sl1, p19, p2tog, p1, turn
Row 18: sl1, k20, ssk, turn
Row 19: sl1, p20, p2tog, turn
Row 20: k22 (you may want to place a marker after 11 stitches, as gusset and toe decrease rows start there. I found at this tight a gauge the marker caused laddering and left it out)

Picking up Gusset stitches:

With the same needle that you've just K22 with, pick up 20 stitches along the side of the heel flap. Pick up one more stitch in the intersection where the heel flap meets the instep stitches, to prevent a hole.

Switch to the instep needle, start the pattern rows again, with a K4p1 row. The instep needle will simply be following the pattern rows all down the foot.

With the empty end of the heel stitches needle, pick up one stitch where the heel flap meets the instep. Then pick up 20 stitches along that side of the heel flap.

(Yes, at this point you will have more than 60 stitches on that needle. It is a bit tricky at first, but gets easier quickly)

Gusset:

Knit across the heel stitches and the other gusset stitches to the last stitch, which you'd picked up in the intersection. Knit it twisted.

Knit next row of pattern on the instep needles.

Heel needle, knit the first stitch twisted, knit to center.

Your gusset rows now start from here.
Round 1 - knit to last 3 stitches of heel needle, K2tog, K1. Instep needle, continue pattern. Heel needle, K1, SSK, knit to center/marker.
Round 2 - K all sts on the heel needle, knit in pattern across the instep needle.
Continue this until the heel needle has 40 stitches on it.

Foot:

For the foot, knit in pattern on the instep needles and in stockinette on the heel needles until the foot is two inches short of the end of the toes.

End on a K1, p4 row.

Toe:

The pattern repeats end here, you will knit all stitches. Again, the row 'starts' at the middle of the heel needle, use a marker if need be.

Round 1 - knit to last 3 stitches of heel needle, K2tog, K1. Instep needle, K1, SSK, knit to last 3 stitches, K2tog, K1. Heel needle, K1, SSK, knit to center/marker.

Round 2 - K all sts.

Continue this until there are 12 stitches left on each needle. Knit one round. Knit to the end of the heel needle. Slip the 4 sts closest to the needle ends over their adjacent neighbors. Use the kitchener stitch to join the remaining instep stitches to the remaining heel stitches.