In a mixing bowl, combine plain flour and salt, gradually pouring in just-boiled water. Knead for about 5 minutes to make smooth dough.

Wrap the dough in cling film and allow it to rest at room temperature for 30 minutes.

In a large bowl, mix together pork mince, spring onions, chives, coriander, garlic, and ginger. Add soy sauces, sesame oil, vinegar, and beaten egg.

Season with salt and pepper to taste, ensuring the filling is well-balanced, then set aside.

Divide rested dough into 8 pieces, rolling into balls. Flatten each ball on a floured surface to create thin circles.

Place a spoonful of filling in the center of each circle, folding to create half-moon shapes. Pinch edges to seal.

Heat oil in a skillet over medium-high heat. Place filled dumplings, smashing them down with a spatula to form flat cakes and fry until golden brown.

Flip, add 1/4 cup of water, cover, and steam for about 1 minute.

Remove lid, let cook for another 2-3 minutes to crisp the bottoms.

Transfer to a serving platter and keep warm while cooking the rest.

Top each taco with fresh toppings and drizzle chili oil if desired. Serve warm.