This combination of shrimp, pineapple, and tomato in a gently sweet-sour tamarind broth is my favorite soup. It goes by various names (hence the title of my post) and seems to be a staple in Vietnamese restaurants, or at least I've never been in a Vietnamese restaurant that didn't serve it.
It's the sort of thing that seems open to endless variation. I've had it with squid or fish instead of shrimp, with okra added, or with rice noodles added. One of my favorite restaurants which made one of my favorite versions of this added thinly sliced hearts of celery. They also used to add little bits of crispy shallot which were a terrific addition. I've had it garnished with cilantro, Thai basil, or mint. Sometimes it has hot peppers in it, sometimes it doesn't. I once had it flavored with cumin which I don't recommend.
Since I no longer have easy access to a Vietnamese restaurant -- there seem to be only two within the Baltimore city limits and I'm not crazy about either of them-- I have taken to making this soup myself. Coming up with a decent version took awhile; the thing that truly had me stumped when first making it was the broth. The internet was full of recipes that suggested adding lime to a broth made with shrimp shells, or just a broth made from simmering the pineapple, tomato, and shrimp with fish sauce but none of them tasted right. It wasn't until I found a recipe from Nicole Routhier's The Foods of Vietnam that I realized that the secret to the broth was tamarind.
Tamarind is a common ingredient in southeast Asian and Indian cooking. It comes from a pulp found in the seed pods of the tamarind tree and it's sold in Asian and Indian markets in 8-oz blocks which are a sticky mixture of the pulp and the seeds. To use it, it is first soaked in boiling water and then forced through a sieve. (For more complete instructions and some funny observations on the nature of tamarind, see this post from Tiny Banquet Committee about making banana tamarind chutney.) The sieved pulp is then stirred into the soup where it adds a gentle and pleasant tartness.
This past weekend I found pineapple at a reasonable price at my supermarket, and because Saturday was a mild, spring-like day (unlike the day before which was 15 degrees at 7 a.m., or the day after which was grey with snow flurries) this soup was our light dinner. It's not a soup for frigid weather -- it's delicate, not rib-sticking. But for a mild winter day, it's perfect.
Spicy and Sour Shrimp Soup
adapted from Nicole Routhier's The Foods of Vietnam
2 ounces of lump tamarind
1/2 cup boiling water
8 ounces medium shrimp (31-35 size), shelled
2 garlic cloves, chopped
1/4 cup, plus 1 teaspoon nuoc mam (Vietnamese fish sauce)
Freshly ground black pepper
2 tablespoons vegetable oil
2 shallots, thinly sliced
3 stalks fresh lemongrass, white bulb crushed and cut into three 2-inch sections
1 large ripe tomato, cored, seeded and cut into wedges
2 tablespoons sugar
1/4 fresh, ripe pineapple, cored, cut into 1/4" slices, and then cut crosswise into small chunks
1 celery heart, the pale inner section, ribs only, sliced very thin
1 teaspoon salt
2 fresh chili peppers, minced (optional)
1/2 cup fresh bean sprouts (optional)
1 scallion, thinly sliced (optional)
2 tablespoons shredded mint or cilantro leaves
1. Soak the tamarind in the boiling water for 15 minutes or until the tamarind is soft. Using the back of a spoon, press the tamarind through a fine sieve into a small bowl.
2. Toss the shrimp with 1 teaspoon of fish sauce, chopped garlic, and pepper. Let stand for 30 minutes.
3. Heat the oil in a 3 quart sauté pan. Add the shallots and lemon grass and sauté briefly without browning. Add the tomato and sugar and cook over medium heat until slightly soft. Add the pineapple and celery and cook stirring for about two minutes.
4. Add 5 cups of water and bring to a boil. Add the sieved tamarind, salt, and the remaining 1/4 cup fish sauce. Turn heat down, and simmer gently for about 5 minutes. Stir in the chiles and bean sprouts if using them and the shrimp. Cook for about 30 seconds, than remove from the heat and allow to sit for about 30 seconds to 1 minute more, or until the shrimp is cooked through. Be careful not to overcook the shrimp here.
5. Add scallions and/or mint or cilantro and serve.
Purported to make 4 to 6 servings but if it's all you're having for dinner, it's enough for two people.