"551" is a famous Chinese restaurant in Osaka. These steamed pork buns can be made easily with two bowls. They're so easy and delicious, I never buy store-bought meat buns. Everyone always asks me for the recipe.
Put an empty bowl on a kitchen scale, and measure the dough ingredients. Add 100 ml of lukewarm water little by little while mixing and kneading the dough. The dough is OK once there are no lumps of yeast.
Cover the bowl with plastic wrap, and leave at room temperature for about 15 minutes. Make the filling in the meantime.
Finely chop the onion and mix with panko.
Put the onion, panko and the rest of the filling in a bowl (place the bowl on the scale beforehand again and measure the ingredients). Mix well and divide into 8 balls.
Divide the dough into 8, and roll out each portion with a rolling pin. If you can make the perimeter of each dough circle thinner than the center, the filling will settle in the middle of the bun.
Spoon a ball of filling on each dough circle and wrap it. If you get filling on the edges, the dough will not close up so be careful! Seal the buns closed properly!
Bring water to a boil in a steamer, line the steamer rack with parchment paper, and place in the buns. Steam over medium heat for 20 minutes, and they're done.
Story Behind this Recipe
A friend taught me how to make these buns. I've adapted the recipe slightly, and have been making it for years. I've always made my own steamed pork buns, so my daughters didn't know until recently that they sell steamed buns at convenience stores.
You don't need to let the dough rise completely like when making bread. If you get filling on the seams (edges) of the dough, the buns won't close up properly, so be sure not to overfill them. If you don't close up the buns securely, they'll open up while steaming, so do be sure to pinch them completely closed.