Cut the four corners of the square won ton wrappers and set aside.
In a large bowl, add ground pork, the diced Chinese sausage, sugar, salt, hoisin sauce, white pepper, soy sauce, and vegetable oil. Mix well.
Incorporate the water into the meat mixture slowly and mix well until the meat becomes a paste. The meat can be used right away or can be placed in the fridge for a few hours or overnight. Cover your bowl with plastic wrap or add the mixture to an air tight container.
Place the wonton wrappers in the center of your palm and add a heaping tablespoon of the mixture into the center of the wonton wrappers. Form a “C” shape with your other hand and squeeze the wrapper around the fillings. Use a spoon or knife to flatten the top of the mixture. Repeat.
To steam, line a steamer basket or dish with parchment paper squares or lettuce/napa cabbage leaves. Add the siu mai dumplings spaced out on the steaming basket. Add water to the steamer and turn the heat on high until the water boils. Add the steaming basket to the pan and place the lid on. Cook for 8 minutes or until done. Remove the lid.
Remove the basket from the heat. Top the dumplings with masago and cilantro leaves. Serve with your favourite dipping sauce.
After step #4, add the siu mai dumplings on a baking tray single layer making sure the dumplings do not touch each other. Place the tray in a freezer for a few hours before adding them into a resealable plastic bag.
Snipping the corners of the wonton wrappers will help create a cleaner look after steaming, but it is optional.