To make the filling: In a large mixing bowl, add the ground pork and salt. Mix well until the pork becomes slightly sticky. Add the shrimp, white pepper, sugar, soy sauce, oyster sauce, Shaoxing wine, sesame oil, and cornstarch. Mix until smooth and sticky. Lift the filling and throw it firmly back into the bowl a few times. Add the shiitake mushrooms, scallions, and ginger, then mix until evenly combined.
To wrap the siu mai: Place a Hong Kong-style dumpling wrapper in the palm of your hand and add about 1 tablespoon of filling to the center. Bring the wrapper up around the filling while gently pressing the filling down, leaving the top open. Top with the minced carrots. Repeat with the remaining ingredients.
To steam the siu mai: Line a bamboo steamer with parchment paper and arrange the siu mai inside, leaving a little space between each one. Bring a pot of water to a boil over high heat. Place the steamer over the pot, cover, and steam for about 10 minutes, or until completely cooked through.
To serve: Serve immediately with soy sauce, chili oil, or your favorite dumpling dipping sauce.