1. **Prepare the Dough:** In a large bowl, combine flour and salt. Gradually add warm water, mixing until a shaggy dough forms. Knead on a lightly floured surface for 5-7 minutes until smooth and elastic. Cover with a damp cloth and let rest for 30 minutes.

2. **Make the Filling:** In a large bowl, combine ground pork, squeezed napa cabbage, green onions, soy sauce, sesame oil, grated ginger, salt, and white pepper. Mix thoroughly in one direction until well combined and slightly sticky.

3. **Assemble Dumplings:** Divide the dough into 4 equal portions. Roll each portion into a long cylinder, then cut into 1-inch pieces. Flatten each piece into a small disc, then roll out into a thin, round wrapper (about 3 inches in diameter). Keep unused wrappers covered to prevent drying.

4. **Fill and Fold:** Place about 1 teaspoon of filling in the center of a wrapper. Fold the wrapper in half to form a crescent. Pinch the edges together, creating small pleats along the curved edge to seal the dumpling. Repeat with remaining dough and filling.

5. **Cook the Jiaozi (Boiled Method):** Bring a large pot of water to a rolling boil. Carefully add dumplings, ensuring not to overcrowd the pot. Stir gently to prevent sticking. Once the water returns to a boil, add 1/2 cup of cold water. Repeat this step two more times. Dumplings are cooked when they float and appear plump, usually 5-8 minutes total.

6. **Serve:** Remove dumplings with a slotted spoon and serve immediately with your favorite dipping sauce (e.g., soy sauce, black vinegar, chili oil).