This is a warm chunky beanie which you can knit up in about 2 or 3 hours. The pattern is similar to the Chunky Mistake Rib Scarf. I used 2 skeins of 50g (about 40m) each. The Beanie is knit in the round, so I used 9mm and 10mm circular needles (40cm length). You will also need 10mm double point needles. 

Cast on 42 stitches with size 9mm needles (40cm circular). Join to work in the round and place marker. 

Rows 1-5: k1, p1 
Row 6: switch to size 10mm needles. K2tog, p1 below, repeat around. (28 st left) 

NOTE: On this row, when you p1 below, you will be purling into a knit stitch every other purl due to the stitch groupings of 3. Do not be alarmed. Purl into the knit stitch and continue normally. 

Row 7: k1 below (into the k2tog stitch), p1 as normal into the p1 below stitch from previous row. Repeat around. 

NOTE: This row is going to look somewhat messy. It will be about four rows of ribbing before the hat pattern starts to look ‘right’. 

Row 8: k1 as normal (into k1 below stitch), p1 below. Repeat around. 
Row 9: k1 below, p1 as normal (into p1 below stitch). Repeat around. 
Rows 10 and on: repeat rows 8 and 9 until hat measures about 17cm in length. This will be about 12 rows of fisherman rib. 

Decrease sequence: transfer to double point needles. 
Row 1-5: k1, p1 in reqular rib around. Keep these rows loose as otherwise they will bunch up from the fisherman rib.
Row 2-3: ssk, p2tog. Repeat around. You start with a ssk as the first stitch in this row (on the left needle) will be a knit).
Pass the wool through the remaining stitches and pull tight. Fasten off. 

NOTE: The decrease sequence will look wrong from the side you are knitting, however the rib pattern will be continued on the underside of the beanie. This is not a problem as the fisherman's rib pattern is reversible.