We make these pot stickers frequently. We use a mushroom filling, but you can use any filling you like, of course.

Ingredients:
Pot sticker wrappers: about 20
Shiitake mushrooms: four medium, about 5 cm across, chopped finely
King oyster mushroom: one large, about the same total volume as the shiitakes, chopped finely
Garlic: four cloves, chopped
Ginger: about a 2 cm length, chopped
Green onions/scallions: about 4, white and green parts sliced separately
Cooking oil: a tablespoon or so, about 15 ml
Five spice powder or other spices of your choice: to taste; I suggest a teaspoon (5 ml)
Soy sauce: a couple of teaspoons, 10 ml
Sesame oil: a few drops
Cornflour/cornstarch (or other starch of your choice): about a teaspoon, 5 ml
Black bean paste of your choice (optional): about two tablespoons, 30 ml
Dipping sauce of your choice

Procedure:

Filling mixture:
Heat cooking oil in a wok or frying pan until shimmering. Add the ginger, garlic, and the white parts of the green onions and saute until fragrant, half a minute or so.
Add the mushrooms and saute, stirring occasionally, until mushrooms soften and begin to brown.
Add the soy sauce, five spice powder, and sesame oil, stir everything together.
Make a slurry with the starch: put the starch in a small bowl, add about twice as much water by volume, and stir well. Drizzle the starch into the mushroom pan with the heat on low, while constantly stirring the mushroom mixture.
Turn off the heat and let the mixture cool until it’s comfortable to handle.

Pot sticker assembly:
If your pot sticker wrappers were frozen, let them thaw at room temperature (still wrapped) until they separate easily and are nice and pliable. Usually half an hour to an hour should be enough, depending on how cold your freezer was.
Put one wrapper on a flat surface. Have a small bowl of water nearby. Put a small amount (about a teaspoon) of filling in the middle. Dip your finger in water and wet a small area around the edge of the wrapper. Fold two opposite edges up and squeeze well to seal. Shape the dumpling any way you like. Here’s how we did ours this time:

These are quite robust. They can wait for a good many hours without harm before you cook them. You can even freeze them, then store them in an airtight container. Whether fresh or frozen, cook them the same way.

Cooking:
Heat up a large flat bottomed skillet. Add a small amount of oil. Place pot stickers flat side down in the skillet and cook them over medium to medium high heat until their bottoms are golden brown (lift one gently to check; do not stir or otherwise move them except to check for browning). Now add a splash (a couple tablespoons, 25 ml or so) of water, reduce heat to low, cover, and let the pot stickers steam until they are soft. Uncover, turn the heat back to medium high, and continue cooking until the bottoms are well browned. Serve with a dipping sauce of your choice. You can add the green parts of your onions to the dipping sauce for a little fresh garnish.