Place the ginger and the white parts of the spring onions into a small bowl. Pour over the boiling water and let it steep until cooled to room temperature.
Divide the shrimp into two portions. Finely chop one half into small chunks for texture, and blend the other half in a food processor until smooth.
Add the minced pork to a mixing bowl. Slowly pour in the cooled ginger-onion water in 3 additions, stirring in one direction after each addition until the mixture becomes sticky and paste-like. This step helps create that juicy, bouncy wonton-style texture.
Add the shrimp paste, chopped shrimp, sesame oil, soy sauce, oyster sauce, and mushroom powder to the pork mixture. Tear the seaweed sheet into small pieces and mix everything together until fully combined. Transfer the filling into a piping bag.
Lightly brush your work surface with oil to prevent sticking.
Quickly dip one sheet of rice paper into water and place it on the surface. Dip a second sheet and overlap it slightly with the first to create a wider wrapper.
Pipe the filling across the middle of the rice paper, leaving about 1 inch of space on both sides. Fold the sides inward, then roll tightly from the bottom up. Repeat with the remaining filling.
In a heatproof bowl, combine the chopped spring onion, sugar, minced garlic, five-spice powder, and chili flakes.
Heat the oil until shimmering, then carefully pour it over the spice mixture to release the aroma. Stir in the soy sauce and lime juice.
Arrange the dumpling rolls on a lightly greased heatproof plate. If using a bamboo steamer, line it with lightly greased parchment paper.
Steam over high heat for 8 minutes. Avoid over-steaming, as the rice paper can become too soft and lose its texture.
Remove from the steamer, pour over the chili sauce, and finish with roasted sesame seeds and extra spring onion. Serve immediately while hot.
