Preparation
Select 30 of the nicest shrimp to be used for garnish in the finished soup. Peel and devein them (keep the shells) and keep them in the refrigerator until the soup is ready. Heat a medium pot over high and add the olive oil, the remaining shrimp and the shells (and heads if you have them). Saute until they turn bright red and develop a pronounced shrimp aroma.
Add the onion, leek, celery , garlic and jalapeno and saute for another five minutes. Reduce the heat and add the chopped tomatoes, lemongrass, chicken broth, potato, and tamarind and bring to a boil. Immediately reduce to a simmer and cook for 25 to 30 minutes or until all of the vegetable have become soft.
Strain the solids from the liquid and mill the solids through the largest die of a food mill. Combine the two and bring back to a simmer. Add the peeled shrimp and simmer for five minutes or until the shrimp are fully cooked. Add the lemon juice and chopped herbs and season to taste with salt and pepper.
Ladle 8 ounces of soup into each bowl making sure to get five shrimp into each.