Boil 500ml water in a wok or large pan
Add 2 kaffir lime leaves (torn into two pieces), 2 one-inch slices of galangal, and 2 half-inch pieces of lemon grass
Boil for 3-4 minutes
Now add all vegetables and tofu you prefer to use - carrot, onion, tomato, tofu, mushrooms, broccoli, etc
Boil for 5-6 minutes until tender yet firm
Now add 1.5 tbsp soya sauce and 1 tsp brown sugar
Boil for another minute and turn off the heat
Add 1 tbsp chopped coriander leaves, 2 tsp lime juice (adjust to taste), 1-2 tsp tom yum paste, and 1-2 tbsp coconut milk
Mix well, adjust salt if needed, and serve hot