Place the dried shrimp in a small bowl and let it rehydrate (about 15 mins); drain and set aside.
¼ cup dried shrimp
Heat oil in a medium pot over medium heat. Add the shallots and garlic and sauté for about 1 minute, until fragrant. Add the rehydrated shrimp and sauté for 2 minutes.
1 Tbsp garlic, 1 Tbsp shallots
Add the tomatoes and cook for 2 minutes, stirring occasionally, until slightly softened.
1 tomato
Pour in the chicken broth and water and bring to a boil over high heat.
1 cup chicken broth, ½ cup water
Add the tofu, then reduce heat to low. Cover and let simmer for 3 minutes.
7 oz soft tofu
Add the chives and mushrooms, if using. Continue to simmer for another 2 minutes, until the vegetables are tender.
1 bunch of garlic chives, ⅓ cup shimeji mushroom
Season with fish sauce, salt, pepper, and chicken bouillon powder. Cook for 2 more minutes to let the flavors come together, then serve.
1 Tbsp fish sauce, ¼ tsp salt, ¼ tsp pepper, ½ Tbsp chicken bouillon