Combine the pork, garlic, and salt in a small bowl and mix until well blended. Set aside.
Bring the chicken stock to a boil in a large saucepan over medium heat. Using a small teaspoon, drop small bits of the pork mixture into the soup (like mini meatballs) and bring the mixture back to a boil again.
Add the tofu, bok choy, and season with the fish sauce, sugar and pepper. Simmer uncovered for 5 minutes before removing from heat.
Serve hot, garnished with the green onions and cilantro leaves.