Put all ingredients for the sauce in a small pan, except for the sesame seeds. Bring it to a simmer and stir until sugar dissolves. Off the heat. Let it cool down completely. Transfer to a jar with a lid and this can be kept in the fridge for about 1 week
Prepare the filling:
Place all ingredients in a large mixing bowl and stir in one direction to combine into a paste-like consistency. Have a taste by boiling a tiny amount in water. Adjust the taste to your preference. Cover and keep this in the fridge while preparing other things. It can be kept in the fridge for 2-3 days if you don't use it on the same day
Assembling:
Read my post below on what type of rice paper are best to use. They are slightly different when you look at the ingredient list
I use the standard size 8.5-inch rice paper. There is 10-inch size rice paper, but that is just too big and you end up with too much extra wrap on top of the dumplings, which makes that part too chewy. If there is 6-inch size, I would prefer that, but I don't think it's available in that size, or the store I went to just didn't have any. Nothing smaller than 6-inches though
Use a scissor and cut the dried rice paper into quarters.
Overlap the quarters, so that the middle is a bit thicker (to support the filling).
Hold on to the wrapper at the center and dip in the water until the wrapper is softened somewhat, about 6-7 seconds (this may vary depending on the brand of the rice paper too). Don't oversoak because you still want it to be firm (but soft enough to be bent so it won't tear). The rice paper continues to soften as you do the wrapping
Put this on top of a cutting board. Scoop the filling, about 2 tablespoons or so on the center.
Gather the softened wrapper around the filling to meet at the center and gently squeeze on the wrapper to "seal" the dumpling. Put the dumplings on a lightly oiled plate and continue wrapping the rest.
At first, you may feel like the dumplings don't seal well.
When you go back to reseal them, they stick together now as the wrappers continue to soften.
Steam the dumplings:
Bring the water in the steamer to a boil. Place a few dumplings on a lightly oiled plate and put this inside the steamer and let them steam for 5 minutes
Make ahead ?
These dumplings are the best when you make and steam them on the same day. The dumplings cannot be assembled ahead and steam later. The rice paper won't hold up so well. BUT, you can keep the already cooked dumplings in the fridge for about 3-4 days. Simply reheat in the steamer before serving
Can you freeze the dumplings ? I don't recommend because the texture of the rice paper changes after freezing