Stir hoisin with soy, chili-garlic, five-spice and sesame oil in a medium bowl. Reserve 2 tbsp of sauce in a small bowl and set aside. Combine remaining mixture with pork, tofu and chives. Stir until very well mixed.
Fill a small bowl with water. Lay a wrapper in the palm of your hand. scoop a heaping tsp of pork mixture onto the centre. Dip an index finger in water and lightly brush it all around the edge of the wrapper. grab the bottom edge and fold the wrapper over the filling, pinching centre of wrapper together to form a half-moon shape that’s open at both ends. Use a thumb and index finger to form a pleat starting in the middle of the sealed edge just right of the centre, working from the inside toward the end of half moon. form 2 more pleats to seal 1 edge of dumpling. Repeat with left side of dumpling. Pinch all the pleats again to ensure the dumpling is tightly sealed. Stand dumpling on a baking sheet on non-pleated end, pressing gently to flatten the bottom. Repeat with remaining wrappers and pork mixture. (Check our how-to video on folding dumplings).
Heat a large non-stick frying pan over medium-high. add oil and swirl to coat bottom. add dumplings in 1 layer in a circular pattern. you may have to do this in 2 batches. Pour in enough water to reach halfway up the dumplings (about 1 cup). Bring water to a simmer. Cook, covered, for 5 min. Remove lid and continue to simmer until water has evaporated, 6 to 8 min. Continue to cook until bottoms of dumplings are golden brown, 2 to 4 more min. Repeat with remaining dumplings, adding more oil if needed. transfer to a large plate. Drizzle with reserved sauce and serve warm. (Make Ahead Tip: Freeze dumplings in a single layer on a baking sheet. Store in freezer bags up to 2 weeks. Cook from frozen, as per directions above. Dumplings may need an extra 1 to 2 min for water to evaporate.)