This Chinese-Italian-French-Japanese dish is slightly more complex than my usual recipes.
The filling is a classic Cantonese pairing of shrimp and chives (use flat, green Chinese chives, which are strongly flavoured, not the more delicate, mild type, Allium schoenoprasum, used in European dishes), and the round wrappers are what you would use for sui gau (boiled dumplings). The dumplings are made into a shape used for Italian tortellini and some types of Korean mandu. The beurre blanc is a traditional French emulsified sauce that goes well with seafood, but here we make it with sake rather than white wine. Confused? Never mind, just try it - the dish is delicious.
Use fresh shrimp, not frozen, for this dish. It takes some time to peel the shrimp, but the results are worth it.
Remove the heads and shells from the shrimp. Slit the shrimp down the back and remove the vein. Use a sharp chef’s knife to hand-chop the shrimp into very small pieces. Do not use a food processor – you want texture in the filling, not a purée. Put the chopped shrimp in a bowl.
Cut the chives into 3mm (⅛inch) pieces and add them to the bowl. Sprinkle the salt over the shrimp and chives, then add the sake, white pepper and cornstarch. Mix thoroughly, then cover the bowl with cling film and refrigerate for at least an hour so the mixture firms up.
Shape the tortellini. Pour some water into a small dish (this is for dampening the edge of the wrappers, so it adheres). Line a flat baking dish with parchment or cling film. Place the stack of dumpling wrappers on a plate.
Put a spoonful of the shrimp/chive mixture in the centre of a dumpling wrapper. With your fingertip, very lightly dampen the edge of half of the wrapper. Fold over the other half of the wrapper so it covers the filling, pressing out as much air as possible. Press on the edges of the wrapper so the filling is securely enclosed. Dampen one corner of the wrapper then bring the other side over. Firmly press the two corners together so they adhere. The dumpling should be plump, but not overfilled, or it might burst. Place the dumpling on the baking tray and use the remaining filling and wrappers the same way; this makes about 40. Place the tortellini slightly apart on the baking tray so they are not touching. After shaping all the tortellini, place the tray in the fridge while making the sake beurre blanc.
Fill a pot of lightly salted water and place it over a high flame so it's ready to boil the tortellini by the time the beurre blanc is ready.
Finely mince the shallot. Cut the chilled butter into 5mm (¼in) cubes. Heat the oil in a small pan placed over a low flame. Add the shallot and a light sprinkling of salt, then cook until the shallot starts to soften. Stir in the sake and increase the heat to medium. Simmer the sake until it reduces to about 10ml (2tsp). Turn the heat to low and, whisking constantly, start adding the butter one or two chunks at a time. Whisk until almost all the butter is melted and emulsified into the liquid, before adding another one or two chunks of butter. Whisk constantly and don’t add the butter too quickly or the emulsion will break (the fat will float to the surface). After adding all the butter, the sauce will be light and cohesive. Turn off the flame and taste the sauce, adding salt, if needed.
When the water is boiling, start cooking the tortellini. Add about a dozen of the tortellini to the boiling water. They will sink to the bottom of the pot, then eventually float to the surface. Stir them occasionally so they don’t stick to each other. After they float to the surface, cook them for about 30 seconds, then taste one to check if the filling is done. Use a large, flat slotted ladle to scoop the tortellini from the water. Drain them briefly in a colander, then blot them gently with paper towels. Put them in a bowl and drizzle very lightly with oil. Mix gently so the tortellini are lightly coated. (If you don’t do this, the tortellini will stick to each other.) Cook the remaining tortellini the same way.
Place the tortellini on individual plates and spoon the beurre blanc over them. Mince the chives and scatter them over the tortellini, then garnish with the greens. Serve immediately.