In the bowl of a stand mixer fitted with the paddle attachment (you can also use a food processor fitted with the steel blade), add the water, baking soda, salt and sugar and whisk to combine. Add the ground pork, breakfast sausage, panko, ginger, garlic, Shaoxing wine, soy sauce, sambal, and sesame oil to the bowl. Beat on medium speed until the mixture lightens a bit in color and becomes almost like a paste, about 1 minute. (If using a food processor, pulse on and off for about 30 seconds). Add in the scallions and chives if using, and beat or pulse again just until the scallions are distributed. Cover the bowl with plastic wrap and refrigerate it while you prep the dough. (The filling can be made up to a full day ahead).
Preheat the oven to 400°F and set a rack in the middle. Line a rimmed baking tray with foil, parchment or a silicone mat.
On a lightly floured surface, roll the puff pastry sheet to approximately 14 x 9-inches. Cut the sheet in half lengthwise to make two long strips. Repeat with the other pastry sheet so you have 4 strips. Take 1/4 of the filling mixture and form it into a long sausage shape down the middle of one pastry strip, leaving a clean border on either side. Repeat with the remaining filling and pastry.
In a small bowl, beat the eggs with 1 teaspoon water. Lightly brush the egg wash over the exposed pastry on either side of the sausage. Fold the pastry over the filling, pressing the egg-washed edges together. Use a fork to crimp the pastry edges together to seal it. Repeat with the other rolls. To make them easier to cut, place the rolls on a tray and pop them into the refrigerator for at least 15 minutes or cover with plastic wrap and refrigerate up to 24 hours
Brush the top and sides of the pastry rolls with the remaining egg wash and sprinkle over the sesame seeds. Cut each long roll into about twelve 1-inch pieces. Transfer them to the baking tray, with a little space in between them. Bake until the pastry is crisp and golden and the filling is fully cooked, 20 to 25 minutes. Serve with sweet chili sauce for dipping.