Half the bitter melon lengthwise, remove the seeds and pulp with a spoon.
Cut the de-seeded bitter melon into thin slices (half-moons).
Chop the chile pepper. (De-seed it and remove the placenta if you want to get the dish less spicy. That also helps not to burn the seeds, if you use a hot gas flame, but it's not usually done in China.)
Stir-fry the bitter melon slices in a bit of hot oil (just to get them done and maybe a bit softer, though they won't be really soft, nor get browned).
Add the chilli and fry it for a few minutes together with the bitter melon slices. (The chilli, also and especially, shouldn't get burned, so don't fry it for too long or too hot - the aroma is intense, anyways.)
Add salt.