Prepare the bitter melon by slicing in half, lengthwise. Remove the seeds with a spoon and then slice each half crosswise as thinly as possible. I would recommend using a mandolin if you have one. It will produce perfectly consistent slices.
2 medium bitter melon
Soak bitter melon overnight in a bowl of salt water.
Remove bitter melon from salt water and squeeze dry. Add to a hot pan with some rice bran oil and fry until slightly crispy. Remove and set aside.
In a medium bowl, combine the soy sauce, Chinese cooking wine, corn starch and sesame oil for the marinade. Add the sliced beef and stir to combine. Set aside.
Heat the oil over medium high heat in pan. Add the garlic and sauté for 30 seconds. Add the marinated beef and stir-fry until the beef is no longer pink, around 3 minutes. Add 1 tablespoon oyster sauce and stir to coat.
Stir in the bitter melon. Add the water and the remaining 2 tablespoons oyster sauce and chilli. Stir and then cook, covered until the bitter melon is crisp tender, around 3 minutes. Turn off the heat and let the pan sit, covered for 5 minutes.