Only experienced endive as part of a salad, I can imagine that it might go sort of slimy if cooked. Maybe a leaf lightly steamed, so it can be folded around a filling. Won't make much of a dent in 6 of 'em though. It's a relative of the Italian Radicchio both being of the chicory family, so there may be some inspiration there. Best of luck.
Edit to add :- Just registered on "good with potato" comment - There's a recipe from the Netherlands called "Stampf" ( No idea if I spelled that correctly)
Potatoes and whatever, cooked together then mashed with butter. Almost anything works - carrot, pumpkin, swede, cabbage, spinach, silverbeet (?swiss chard) and so on. I've even just cooked the potatoes and then mashed in any heated left over veg. My grandmother used to make a version that she called King Edward Potatoes (they are a red kind) where she used swede because we kids wouldn't eat swede . . . oh, the trickiness of the older generations.
