I can't access the pattern (as i'm not registered with patternfish), but I think they mean the following:
Cast on three stitches in your normal way on the circular needle.
Hold the needle 'straight' as your right needle and hold the knitted piece as your 'left' needle.
Using the working yarn from the skein used to cast on the 3 stitches pick up and knit
the 13 stitches from the 'left' needle to the 'right'/circular needle so you have 16 stiches on the circular needle with the knitted piece hanging down below the needle.