Combine all pork, mushroom, garlic, onion, hoisin sauce, ginger, sesame oil, chili sauce, and white pepper in a large bowl.  Get your hands in there and mix it.  Mix it real good.

Spoon about 1 heaping tsp of filling onto a wrapper.  Wet your finger with water and moisten the edges of the wrapper and fold it in half to close it, pinching and folding the edges closed with whatever method works best for you and the wrapper that you're using.  Repeat until you've run out of meat.

Heat 1 tbsp of the vegetable oil in a frying pan, heating on med-high heat.  Once the oil is hot, lower the heat to medium and place a batch of dumplings into the hot oil, taking care not to overcrowd them too much.  Cover the pan and let them cook for 3-5 minutes, depending on how full you stuffed them.  Check them at 3 minutes to make sure they're not burning too much, you want them brown and crispy, but still edible.

Add about 1/4 cup of water to the hot pan and cover things once more to steam the dumplings for another 2-3 minutes.  Remove lid and increase to high heat if needed to evaporate any water.

Repeat for each batch of dumplings, and serve with your choice of dipping sauce.