The pattern is the Chunky Mochi Fan Stitch Scarf. It's effective but very simple; after a few repeats you can remember it and just sit back and not bother to look at the pattern.
It's the biggest yarn I've made, and these are the biggest needles I've used (12mm). Not sure of their origin, but they are with a bunch of my grandmothers, so that makes the scarf a little more special.
It's about half the finished length, and that was a single sitting - it's superquick working on this scale! It's also harder work - much more physical moving those big needles around.