I just plugged "arrowhead cabbage" into Google, and WOW it's a popular CSA offering! I didn't find a lot of facts about arrowhead cabbage specifically, but if you're looking for a recipe, there are plenty of them out there. Two that looked really good are a cabbage pallya and a cabbage and radish slaw. Basically, if you shred it up and use any sort of vaguely Asian dressing on it, you should be good to go. Arrowhead cabbage is said to have thin, tender, and sweet leaves that are wonderful eaten raw. Of course, being cabbage, it has practically no calories, so let loose with the dressing--why not?