Imagine my surprise to discover this dish on the island of Reunion, a lush volcanic west of Madagascar. There, chokoes are grown in abundance, so much so that one of the valleys (the deep green valley of Salazie where vegetables and fruit are cultivated) is literally choked by choko vines. When peeling chokoes, do so under running cold water (or with gloves on) as they are very slippery.
Blanch the sliced chokoes in rapidly boiling salted water for 1 - 2 minutes. Drain well and place the chokoes in a buttered gratin or flat ovenproof baking dish. Spoon over the cream then sprinkle liberally with the cheese. Cover and place in a moderate oven (350ºF/180ºC) for about an hour, or until choko is tender. Remove cover for the last 15 minutes to allow top to brown.
Note: try chokoes in a salad or stir-fry - for extra crunch, don't blanch before using. Like tofu, they will absorb the flavours in the dish. In the mid 20th century, they were often added to stewed pie apple to bulk up the quantity.