Make the filling: Heat a skillet on high heat and coat the pan with a tablespoon of oil. Add the mushrooms, 1 teaspoon of the dark soy sauce, sugar and smoked paprika. Stir this mixture well – until the mushrooms are evenly coated and the sugar dissolves. Sauté for 2-3 minutes until the the mushrooms are relatively dry and start to crisp up. Add the cooked rice and stir-fry with the remaining soy sauce and chopped scallions. Season with salt, if necessary. Transfer the mixture to a large plate to let it cool completely before wrapping.

Make the wrappers: In a large bowl, mix the flour and salt together. Whilst stirring continuously, gradually pour in the just-boiled water and stir until the mixture begins to clump together in little clusters. Knead these together until a large ball of dough forms. Turn it out onto a clean work surface and knead for 10 more minutes, or until the dough becomes smooth and elastic (like Play Doh). If it's sticky and too wet, add another tablespoon or two of flour. If it's too dry, add another tablespoon of hot water. Cover the dough with a clean, damp dish cloth and set aside for 20 minutes.

On a clean, lightly floured work surface, roll the wrapper dough into a long, skinny piece about 1-inch in diameter and divide it into 20-22 equal pieces. Keep these covered with a damp dish cloth while you're assembling them. Use a rolling pin to flatten each of these pieces and roll them out to thin 1/16-inch (3mm) rounds (it doesn't matter if they're not perfect circles), about 4" in diameter – try to go thin as possible without tearing the wrapper when assembling.

Assemble the shao mai: Place one dough round in the palm of your hand and add 1-2 teaspoonfuls of the filling in the center of the dough round. Carefully spread this in an even layer, leaving a 1/4" (6mm) perimeter of wrapper uncovered. Make a circle or "OK" symbol with your thumb and index finger. Rest the filled dumpling round on top of this circular opening of your hand, and use a butter knife to push the filling down whilst forming pleats around the whole thing. Once the bundle is formed, like a filled cup, gently squeeze the pleats together so the folds don't unfurl. Place the assembled shao mai onto a parchment-paper lined tray and continue until you run out of wrappers or filling.

TO STEAM: Stand each shao mai up in a steamer basket lined with a thinly sliced carrot or radish round underneath each one. Pour ¼ cup or 1-inch (3 cm) of water into a wide pot or wok. Place the basket into the pot, ensuring that the water does not reach the level of the dumplings. Cover the basket and bring the water to a boil. Turn the heat down to a medium-low heat and let steam for 5 minutes .