It's a big vegetable like a cross between a cucumber and a potato. You can treat it a bit like a tough courgette. Steaming it the other day didn't work out well. But today I tried frying it with chicken, in a mediterranean fashion, and yeah that worked out.
This simple thing is to serve one and takes less than 20 minutes:
Slice the dudhi down the middle and then into slices about 1cm thick. Get some oil nice and hot in a big frying pan and add the dudhi. Fry the dudhi for a total of maybe 15 minutes, but adding more things about half-way through as follows.
While the dudhi is cooking, dice the chicken breast. Add some salt and pepper to a handful of plain flour on a plate, and toss the chicken in the flour, to coat evenly. Add it to the hot pan, making sure the chicken pieces are in the hottest and oiliest bit of the pan so that they're going to fry and cook. Slice the garlic and add that too.
When the food is ready to serve - you need to be confident that the chicken has had time to cook through - turn the heat off, then sprinkle the basil leaves on top of everything. Also sprinkle a small splash of water on top, which will instantly turn to steam and just help the basil along a touch. Stir briefly and serve, with bread or pasta.