Thai seafood tom yam soup

Ingredients
150g fresh shrimps
150g fish fillet ( cut into rectangular slices)
10pcs button mushroom
1 tomato ( cut into wedges)
1 big onion ( cut into big pieces)
3 pcs Kaffir lime leaves ( daun limau perut )
3 slices lengkuas
2 stalks lemon grass ( use the top white portion )
1 red chill ( cut into small pieces)
1 tbsp fish sauce
1 tbsp light soya sauce
1/4 tsp salt
*some lime juice ( if you prefer sour taste)

Preparation
1. Boil 1 litre water in pot.
2. Add in all the ingredients except fish fillet and shrimps to boil for 15 minutes.
3. Put in the fish fillet and shrimps to boil until cooked.
4. Serve hot.