Add flour into a big bowl. Very slowly drizzle water in batches onto the dry flour, and whisk with a pair of chopsticks. Try to mix in a way that creates many small dough pieces, without them clumping together. It’s important to add a very small amount of water at a time, and stop, then mix very thoroughly. At the end, there should be little or no dry flour left, and small dough flakes ranging from pea-sized to blueberry-sized (*Footnote 2).

Heat oil in a medium pot (4-qt) over medium-high heat until hot. Add the ground pork. Cook and chop the pork into small pieces until cooked through and the surface is lightly browned, 4 to 5 minutes.

Add the scallion whites and ginger. Stir a few times to release fragrance. Add the tomato, light soy sauce and sugar. Cook and stir until the tomato starts to fall apart.

Add the chicken stock and bring to a boil. Turn to medium heat. Add the dough flakes in by slowly pushing them into the pot, dropping them into empty space so the dough doesn’t clump together. If the dough starts to clump together, immediately use a pair of chopsticks to stir and separate the dough into small pieces. After all the dough pieces are added, keep stirring to make sure they don’t clump together. Cook for 2 to 3 minutes until the dough is cooked through.

Add the baby bok choy and cook for 1 to 2 minutes, until wilted.

Turn to medium-low heat. Slowly drizzle in the beaten eggs. Let the eggs sit for 30 seconds, then stir to form ribbons.

Turn off the heat. Add the chicken bouillon, white pepper, sesame oil and scallion greens. Stir to mix well. Taste the soup and adjust seasoning if needed. Serve hot as a main dish.