Cast on 47 sts and distribute 10, 11, 13, and 13 sts onto four needles. The beginning of the round is between needles I and IV. Begin the twisted ribbing and the cable pattern in the round from row 1 of chart: p1, *k1 tbl (= through the back loop), p1*, repeat *–* 9 more times, work the 26-st pattern on the chart. Work the sts on needles I and II in ribbing. On needles III and IV, work rows 2–12 of the cable pattern on the chart, then keep repeating rows 13–24.
Note: When you have worked row 18 of the cable chart, switch to working in stockinette st on needles I and II. On needles III and IV, continue the cable pattern.
When you have worked 2 rows in stockinette st, begin the increases for the thumb gusset: knit all sts on needle I, knit all sts on needle II until 4 sts remain. Make 1 (m1 = pick up the strand of yarn between the sts onto your left-hand needle and knit it through the back loop), k2, m1, k2.Continue working the stockinette st and repeat the gusset increases every 3rd round for 5 more times. 2 sts increased on the gusset each time. When you have finished the increases, work 1 round. Work through the next round until you reach the gusset. Move the 14 gusset sts on hold onto a piece of scrap yarn.
Cast on 2 sts at the gusset and continue the patterns until you have worked rows 13–24 of chart I for 4 times. Then work rows 25–34 of the chart. Work row 35, 4 sts decreased on the cable pattern. Work row 36, 2 more sts decreased on the cable pattern. At the same time, decrease 1 st on needle I. 40 sts now on the needles, 10 sts each. From now on, purl all cable sts.
Begin the decreases for the top: at the beginning of needle I, k1, skp (=slip 1, knit 1, pass the slipped stitch over). At the end of needle II, k2tog, k1. At the beginning of needle III, k1 tbl, p2tog. At the end of needle IV, p2tog, k1 tbl. Work these decreases every round until 8 sts remain in total.
Break the yarn, pass it through the remaining sts and securely weave in the yarn ends.
Work as the mirror image of the left-hand mitten. Work the thumb gusset 2 sts from the start of needle III.
Pick up the sts on hold and 2 additional sts from the base of the thumb. Distribute these 16 sts on three needles and work stockinette st in the round.
When you have worked for 5 cm or past the halfway point on your thumb nail, work the decrease. At the end of each needle, k2tog until 6 sts remain. Then k1 and pass the remaining sts over. Securely weave in the ends.
Steam the mittens lightly.