Wrap the tofu in a paper towel, place it in a microwave-safe container, and heat it in a 600W microwave for 2 minutes without covering. Let it cool and tear it into bite-sized pieces. Slice the bitter melon in half lengthwise, remove the seeds and pith with a spoon, and cut into 5mm slices.

Thinly slice the onion. Crack the egg into a bowl and whisk it.

Heat salad oil in a frying pan over medium heat. Add the tofu and stir-fry until golden brown.

Push the tofu to the side of the pan, add the bitter melon and onion, and stir-fry until softened.

Add the shrimp and stir-fry until they turn pink.

Add the seasonings (sake, salt, pepper, soy sauce) and stir to coat all ingredients evenly.