3-4 fresh chiles, stemmed, seeded and chopped
1 red, yellow, or green bell pepper (chopped)
1 red onion, chopped (about 2 cups)
3 fresh lemongrass stalks (about 4 inches of the tender lower stalk), minced
3 garlic cloves, minced or pressed
1 tbsp grated fresh ginger root
1 cup water
1 tbsp canola or other vegetable oil
4 cups water
2 tsp tamarind concentrate
2 cups unsweetened crushed pineapple, undrained (20-oz. can)
2 tbsp soy sauce
1 lb firm fish fillets, such as sea bass, red snapper, or mahimahi, cut into 2 inch chunks
1/4 cup whole or chopped fresh cilantro leaves
1/4 cup fresh basil chiffonade
1/2 cup mung sprouts and/or peeled, seeded, and diced cucumbers
In a food processor or blender, whirl all of the chili paste ingredients until very smooth. If some lemongrass pieces aren't well pureed, just strain the soup through a colander to remove them before you add the tamarind. In a nonreactive soup pot, warm the oil. Add the chili paste carefully to avoid splattering. Increase the heat to high and cook, stirring frequently, for 10 minutes. Add the water, cover, and simmer for at least 20 minutes.
In a small soup bowl, add a ladlefull of the chili paste broth to the tamarind concentrate and stir to dissolve. Stir the dissolved tamarind back into the soup pot. Strain the broth through a fine sieve *if you prefer* a smoother soup.
Add the pineapple and soy sauce. Add the fish and simmer for 5-10 minutes, until the fish is tender and cooked.
To serve, divide the cilantro, basil, and mung sprouts and/or cucumbers among the individual bowls and ladle the soup on top.