Take the vegetable stock in a large pan and place it over medium heat. 

Once the stock comes to a gentle boil, reduce the heat to low.

Add the coconut milk.

Slice the galangal, tear the kaffir lime leaves, lightly bash the lemongrass stock and chop it into big pieces and add all these to the pan.

Let this simmer for about 6-8 mins.

Now add in the smashed chillies, sliced tofu, sliced mushrooms, soya sauce, sugar and salt to the pan.

Let it simmer for a further 5-6 minutes or until the mushrooms are cooked.

Now take the pan off heat and add in the lime juice 1 tbsp at a time, give it a taste and add more if you need.

Serve this soup hot topped with chopped spring onions.