Add dried shrimp to a bowl. Cover with water and let sit for 10 minutes to clean the shrimp.
Bring 4 cups of water to a boil.
Add chicken breast, onion, dried shrimp, salt, and sugar. Scoop off any impurities you see.
Let it simmer for 30 minutes.
Add tomatoes and chicken broth. Simmer another 15 minutes.
Take out the chicken and shred it into small pieces. Add it back to the broth.
Lastly, add in the silken tofu. The broth should be done at this point.
Ladle soup into bowls. Top with cilantro, green onions, and fried shallots and serve.