Heat 1 tablespoon of oil in a large nonstick skillet over medium-high heat until hot. Turn to medium heat and pour in the egg mixture. Scramble the eggs and chop them into small pieces using your spatula, until the eggs are just cooked through. Transfer to a large bowl to cool.

Add 1/2 tablespoon of oil and the mushrooms. Cook over medium-high heat until the mushrooms are browned and all the liquid has evaporated. Transfer to the same bowl with the eggs.

Add the cubanelle pepper, oyster sauce, white pepper and sesame oil. Mix everything together. Taste the mixture. It should be slightly salty by itself.

Prepare a small bowl of water on the side. Use your finger to wet the edge of the dumpling wrapper. Scoop about 1 tablespoon dumpling filling and place it in the center of the wrapper. Hold the dumpling with one hand and start sealing the edges with the other hand. After folding, press the edges again to seal well. You can use any way you like to fold the dumplings as long as you’re comfortable with it.

Now you can freeze these dumplings if you don’t plan to cook them immediately. Place them onto a baking tray and seal it with plastic wrap. You can store the dumplings in the freezer for up to 1 month. Once the dumplings are completely frozen, after about a day, you can transfer them to a gallon bag to save freezer space.

Cook the dumplings in batches. Heat about 1 tablespoon oil (*Footnote 2) in a nonstick skillet over medium heat until hot. Add dumplings and cook until the bottom turns golden. Flip the dumplings to brown the other side until pale golden. Pour in 2 tablespoons of water and cover. Cook until the dumplings are cooked through, 2 to 3 minutes. Uncover, continuing to cook until the bottom side turns golden.

Serve hot by itself, or with dumpling dipping sauce, or a touch of Chinkiang vinegar.