Prepare the prawns
Pat the prawns thoroughly dry with paper towel.
Cut them into approximately 5–7 mm pieces.
Don't mince the prawns into a paste.
Part of what I want in these siu mai is actual pieces of prawn distributed throughout the pork filling, so they should still be noticeable when you bite into one.
Set aside in the refrigerator while preparing the pork.
Prepare the mushrooms
Finely mince the mushrooms.
You want them considerably finer than the prawns.
The mushroom isn't there to create obvious chunks. It should disappear into the filling, contributing moisture, texture and savoury flavour.
Start mixing the pork
Place the pork mince into a large mixing bowl.
Add the salt, sugar and white pepper.
Mix vigorously in one direction for approximately 2–3 minutes.
As you continue mixing, you'll notice the pork change from loose mince into a much stickier and more cohesive mixture.
This is important.
Siu mai filling shouldn't have the loose, crumbly texture of cooked mince. Developing that sticky mixture helps produce the springier texture we're looking for.
Add the egg and potato starch
Add the egg white, potato starch and bicarbonate of soda.
Continue mixing in the same direction for another 1–2 minutes, until completely incorporated.
The mixture should now feel noticeably sticky.
Add the mushroom and sesame oil
Add the finely minced mushroom and sesame oil.
Mix until evenly distributed.
At this stage the filling should be soft, sticky and cohesive rather than dry or crumbly.
Fold through the prawns
Add the chopped prawns.
Fold them through the pork mixture until evenly distributed.
Don't aggressively mix the filling once the prawns have been added.
We've already developed the pork mixture. Now we're trying to preserve those little pieces of prawn.
Chill the filling
Cover and refrigerate for approximately 20–30 minutes.
This gives the mixture time to firm slightly and makes the siu mai considerably easier to shape.
Cook a test piece
Before wrapping the entire batch, take approximately a teaspoon of filling and cook it completely in a small frying pan or microwave.
Taste it.
Remember that the finished siu mai will also have a wrapper, so the filling should be well seasoned on its own.
Adjust the salt or white pepper if necessary.
Fill the wrappers
Place a siu mai wrapper across the opening between your thumb and index finger.
Spoon the filling into the centre.
Gently push the filling downward while bringing the wrapper up around the sides.
The top remains completely open.
Shape the siu mai
Gently squeeze the sides to create the characteristic siu mai shape.
Flatten the bottom against your work surface so the dumpling stands upright.
Use the back of a spoon to smooth the exposed filling.
Aim for approximately 30 g total weight per siu mai, including the wrapper.
I'd weigh the first several.
Once you've made enough of them, you'll quickly get a feel for how much filling each wrapper needs.
Garnish
If using carrot, place a tiny amount of finely diced carrot in the centre of each siu mai.
It's there primarily for colour, so you only need a little.
Prepare the steamer
Bring your steaming water to a strong boil.
Line the steamer with perforated baking paper, a steamer liner or cabbage leaves.
Arrange the siu mai upright with a little space between each dumpling.
The steamer should already be producing plenty of steam before the siu mai go in.
Steam
Cover and steam for approximately 8–10 minutes, depending on the exact size of the dumplings and your steamer.
The pork and prawn filling needs to be completely cooked through.
When making the recipe for the first time, check one from the centre of the steamer. The filling should reach at least 75°C.
Serve
Serve immediately while hot.
They're good enough to eat by themselves, although chilli oil, chilli sauce, soy sauce or Chinese mustard all work alongside them.