Heat the sesame oil in a pan. Add ginger, garlic and red chilli flakes. Cook for 30 seconds.
Stir in the vegetables and crumbled tofu. Mix in the soy sauce, salt and pepper. Cook for 3-4 minutes. Taste and adjust for seasoning.
Let this mixture cool a bit.
To assemble the dumplings, place wrappers on a work surface. Spoon 1 teaspoon of the tofu mixture into the center of each wrapper. Using your finger, rub the edges of the wrappers with water. Fold the dough over the filling to create a half-moon shape, pinching the edges to seal, making pleats as you do so.
Heat vegetable oil in a large skillet over medium heat. Add potstickers in a single layer, pleat side up and cook until the bottom is golden about 2 minutes . Add 2 tablespoons of water and quickly cover the pan. Let cook for another 2-3 minutes.