Grind the ingredients together for red curry paste till smooth and set aside.
Heat 1 tsp of oil in a pan, add in the curry paste and saute till the raw smell leaves and oil separates from this..Set aside..
Take water, lemon grass and lime leaves in a sauce pan and bring it to a boil. Now simmer this for 10 mins to infuse the lemon grass flavour. You can strain this if you want. Now add the stock back into the pan.
Add in the sauted curry paste along with the oil and mix well.
Add in mushrooms, tomatoes, spring onion white and mix well. Cook till mushroom is cooked.
Now add in tofu, green chillies soy sauce, salt, sugar and mix well.
Add in lemon juice, spring onion green and coriander leaves and mix well.