Cabbage or kale.
Especially popular in the winter in lachanontolmades and λαχανοσαλάτα (lachanosaláta). At its most basic the salad is Greek cole slaw, grated white cabbage with olive oil and lemon, but other recipes are more elaborate.
Chief among these is Polítiki Kouzína's πολίτικη σαλάτα (politiki salata), which uses both red and white cabbage, grated carrot, roast red peppers and capers in a dressing of olive oil, garlic, red wine vinegar and mustard.
Image by pizzodisevo 1937