Cut the onion in half. Thinly slice one half (for the curry) and finely chop the other half (for the meatballs). Microwave the chopped onion for 1 minute at 600W, then let it cool. Slice the bitter melon in half lengthwise, remove seeds and pith, and thinly slice. Sprinkle with 1/2 tsp salt, massage, let sit until softened, rinse, and squeeze out excess water. Thinly slice the garlic.

In a bowl, mix the ground meat, chopped onion (for meatballs), and the ingredients marked with ☆ until sticky. Divide into 12 portions and shape into balls.

Heat vegetable oil in a frying pan over medium heat. Add the garlic slices and cook until golden brown, then remove. Add the meatballs and cook until browned on both sides, then remove.

Add the sliced onion (for curry) to the pan and sauté until softened. Return the meatballs to the pan, add water, cover, and simmer on low heat for about 10 minutes.

Add the curry roux to the pan and stir until thickened. Simmer for another 5 minutes, then add the bitter melon and mix well.