Picot Cast On?


I want to make this adorable hat for my nephew:


But I am not sure how to do a picot cast on (?). Here are the instructions:

Using Alpaca Regal, cast on 56 sts using picot cast-on as follows: *cast on 3 sts, cast off 1 st, slip stitch now on right needle back onto left needle (2 sts on left needle), repeat from * until there are 56 sts on left needle. This will form a scalloped bottom edge for the hat.

I am not sure what they mean by “cast off one stitch.” Is there a video somewhere or can someone help?!

Thank you!

You cast on 3, then you knit 1, knit another one, pull the first stitch over the second and off the needle, as if casting off, then you put the loop from the right needle to the left needle again.

Then you cast on 3 stitches again and repeat.