Cast on 56 stitches using the 3 mm needles and worked 1 row in k2p2 rib. Then swapped to 2,5 mm needles.
Knitted totally 21 rows of ribbing.

Continued with pattern.

Started heel flap after 18 cm.
Made the Slip Stitch Rib for the heel flap.

I didn´t understand what to do just before the kitchener stitches. So I worked with 20 stitches instead of 16.