Place garlic, ginger, lemongrass, lime leaves, lime slices in a pot; pour chicken stock and water; bring to a boil; discard lemon grass lime leaves, ginger and lime slices; continue boiling
Add in fish sauce, lime juice and Vegeta; stir well, bring to boil again
Add in cubed tofu, stir slowly, bring to boil again
Lastly add in shrimps followed with mushroom, chilies, and green onion, simmer for 2-3 minutes
Serve immediately