Countryside Sour Soup (Somlaw Machue Srae) សម្លរម្ចូរស្រែ is another classic Cambodian dish. To the best of my knowledge I believe this soup got it’s name because of the ingredients that were available to rice paddy farmers in the countryside. Fish and rice paddy herbs (Ma-Om) ម្អម were abundance to the locals. They are easily accessible because they can be found in the rice paddy. You can also use holy basil (maress prov) ម្រះព្រៅ or regular Thai basil (chee krohorm) ជីក្រហម. A variety of vegetables can used in this soup such as water spinach (trokoun) ត្រកួន, taro stem (kdard) ក្តាត, young banana tree stems (derm jake) ដើមចេក, tamarind leaves (troeuy ompil) ត្រួយអំពឹល or lotus root (mum chook) មើមឈូក like what I am using. I got these fresh lotus stems from the Asian Supermarket in Stockton while visiting my Parents. The beautiful colors was what caught my attention. Although as you can see from the image that once it’s cooked it doesn’t maintain these pretty color. 
You can also use the jar one that has been cleaned and soak in brine.You can use any type of fish you want. What I have here are small catfish that my Mother had fished and cleaned for me. 
This soup cook very quickly so make sure you prep everything in advance.
Ingredients
4 small fish or 2 big fish steaks
½ lb lotus root
1 tablespoon tamarind soup base (Knorr)
½ tablespoon pickled fish (prohok)
1 teaspoon salt
1 teaspoon sugar
4 kaffir leaves
½ cup holy basil leaves
4 cups of water
2 chilies (optional)
Method:
If using fresh lotus stems like I did wash and peel the outer skin. Cut into 1 inch pieces and set aside. If using the one from a jar, just drain and give it a quick rinse.
Put kaffir leaves in a pot with 4 cups of water and bring to a boil. Add pickled fish and carefully add the fish. Continue to cook until the fish is just about done.
Next add tamarind soup base and sugar. Taste first before adding the additional 1 teaspoon salt because pickle fish and the soup base has some salt content in them already. Sour should be the main flavor.
Once you are satisfy with the flavor turn heat off and add the fresh herbs. Stir to combine then ladle into a bowl. Garnish with chili peppers and serve with steamed rice.
look good
Hi, can you find prohoc in the uk?
Tigerlilly,
If you have access to large Asian grocery store that carries products from Vietnam and Thailand, then you are most likely to find a jar of “pahok” fermented fish on the shelf. It should be in aisle where they have all the sauces in a jar. Good luck!