CO 2x 10 sts with CC
increase every second round until 60 sts. Switch to MC.

Next round: move BOR 5 stitches back so the koffieboontjes are at equal heights on both sides of the purl stitches.
Knit one round plain

The pattern is a repeat of four rounds with a “koffieboontje” pattern flanked by purl stitches. To keep the edges of the large knit area trim, it is flanked by a ktbl on both sides.

Start pattern:

1: (p1, slip 1, k2, psso2, p2, k3, p1, ktbl, k17, ktbl, p1) twice
2: (p1, k1, yo, k1, p2, k3, p1, ktbl, k17, ktbl, p1) twice
3: (p1, k3, p2, k3, p1, ktbl, k17, ktbl, p1) twice
4: (p1, k3, p2, k3, p1, ktbl, k17, ktbl, p1) twice

Repeat these four rows until you’re ready to start on the gusset.

The increases for the gusset are made in between the p2 stitches. I used m1p.

Keep increasing every second round until you have 15 gusset stitches on either side (30 sts in total)

Switch to CC and knit the heel.

The foot has 16 coffeebeans, so the leg will as well. After finishing the heel flap, return to knitting the 4 row pattern and repeat until 16 coffeebeans in the leg.
Finish with a row 2.

Switch to smaller needles. Knit the ribbing as follows:
(p1, k3, p2, k3, (p2, k2) five times, p1 ) x2