A few years ago, I knitted a pair of mitts for a musician friend, and he eventually lost one. He seemed appropriately heartbroken, and I was lucky enough to have a bit of the discontinued yarn left in my stash. I'd made up the pattern though, so I had to rework it from memory and by using the first mitt as a guide.
It took a few attempts, but just in case he loses it yet again, here are my notes:
Super Bulky Fingerless Mitts
yarn: GGH Travertino (on the thinner side of super bulky)
CO 28 stitches and join in the round. K2P2 for 12 rounds, then begin thumb increases every 3 rounds 3x. Work 8 rows in pattern. Put thumb on holder. CO 2 stitches and rejoin in round. Work 12 rows in ribbing. Cast off. Pick up 2 extra stitches for thumb and work 3 rows in pattern. Cast off.