Darn mittens are kicking my behind

I have a pattern that, near the thumb area, it says to knit 1,6 cast on 5, slip 7 stitches onto the holder. How in the world am I supposed to cast on in the middle of a mitten? I’m working on 5 dpn’s.'s.

To cast on in the middle of the work you have to do it on the needle where the working yarn is. It can be backward loop, or move the needle to the other hand and use the knit or cable CO. Then put the needle back and continue on.