You could p and k into the same stitch. Purl as normal but don’t slide it off, then bring the yarn to the back and knit into the same stitch and then slide it off.
Do just as is written, purl into the st, but don’t remove it from the needle, then knit into the same st, remove sts, and u will have your increase. Are you doing the cabled gauntlets from Knitty Gritty?