I got this recipe from Authentic Recipes from Vietnam by Trieu Thi Choi and Marcel Isaak. The recipe as it appears in the book is in blue; my changes are in black.
Bun Rei (Crab Soup with Tofu and Rice Noodles)
2 lbs (1 kg) fresh medium crabs (I used imitation crab meat that was already cooked)
6 cups (1 1/2 liters) water
1/2 teaspoon sugar
1/2 teaspoon dried shrimp paste belachan, crumbled (I substituted 1/2 lb cooked, deveined, tail removed, shrimp)
1/2 teaspoon salt
2 tablespoons oil
1 cake pressed tofu (about 7 oz /200 g), cubed (I used firm tofu)
3 cloves garlic, crushed
2 tablespoons thinly sliced baby leeks (2 celery stalks, finely diced)
1 large tomato, cut in wedges (4 plum tomatoes)
2 tablespoons fish sauce
2 tablespoons tamarind juice (see below) (left out)
8 oz (250 g) dried string-like rice noodles (bun) or rice vermicelli
1 spring onion, sliced, to garnish
Sprigs of coriander leaves (cilantro), to garnish (put about 2 - 3 tbsp in soup while seafood was cooking)
Accompaniments:
1 finger-length red chili, deseeded and thinly sliced
1/2 cup (25 g) bean sprouts
1/2 cup (20 g) minced coriander leaves (cilantro)
1/2 cup (20 g) mint leaves
1/2 cup (30 g) sliced water spinach (kangkong)
1/2 cup (20 g) sliced saw-leaf herb leaves (ngo gai)
1/2 cup (70 g) sliced banana blossom or cabbage
1 lime, sliced (left out all accompaniments except lime which I cut in eighths and let each person squeeze into their bowl before eating)
1) Scrub and rinse the crabs thoroughly. Detach the claws from each crab. Lift off the carapace and discard. Scrape out any roe and discard the gills. Rinse well and halve each crab with a cleaver.
2) In a large saucepan or stockpot, bring the crabs and water to a boil over high heat. Reduce heat to medium, season with the sugar, shrimp paste and salt, and simmer for about 5 minutes. Remove the crab from the soup and set aside to cool. Keep the soup hot over very low heat.
3) Crack the crab shells and remove the crabmeat from the shells. Discard the shells. (I did steps 1 - 3 after step 4. For steps 1 - 3: I boiled the water along with cilantro. I then added the shrimp and the crab and waited a few minutes till the meat was heated through. I then added the vegetables from step 4.)
4) Heat the oil in a wok or skillet over medium heat. Pan-fry the tofu cubes until golden brown, about 2 minutes on each side. Remove and set aside. Reheat the oil and stir-fry the garlic until golden brown and fragrant, about 1 to 2 minutes. Add the baby leek and tomato and stir-fry until tender. Season with the fish sauce and tamarind juice. Remove from the heat and add the mixture to the hot soup.
(Instead of using a skillet I used a large pot. I fried the tofu first. I removed the tofu from the pot. Then I fried the garlic, celery, and tomatoes all together in the same pot. I removed them and set them aside. I then filled the pot with the water. See note for steps 1 - 3. After steps 1 - 3, I returned the tomato mixture to the pot which now had the crab soup in it. I added in the fish sauce. I kept soup hot over low heat.)
5) Bring a separate pot of water to a boil. Boil the dried rice noodles until soft, 5 to 7 minutes or longer as needed. Remove and rinse with cold water, then drain.
6) Place the rice noodles and fried tofu in individual serving bowls. Top with some crabmeat and pour the hot soup over. Garnish with spring onion and coriander leaves (cilantro). and serve hot with the Accompaniments. (No changes to Step 5 and 6 except since I never removed the crabmeat from the soup and the cilantro was already in the soup, I just ladled the soup over the noodles. See Accompaniments for further notes.)
Serves 4 to 6 | Preparation time: 40 mins | Cooking time: 30 mins
* To make tamarind juice, mix 1 tbsp of dried tamarind pulp with 2 tbsp of warm water then mash well and strain to remove the seeds and fibers.
The only complaint I had was that the noodles were rather tasteless. Maybe I should have cooked them in the water. Or left them out entirely. Also I thought some spice, like 1 tsp or so of chili powder may have made the soup broth taste better.