In Vietnamese, this is called bún cá Kiên Giang. See the main blog post for many pointers. If rau ram isn’t available, use ½ cup coarsely chopped cilantro. This recipe was inspired by Albee Tran of Son Fish Sauce. See Notes below for tips on making the broth in a pressure cooker.
To ensure clear broth, parboil the bones (flavor won’t be lost). Put them in a 6 to 8-quart pot with enough water to just cover. Bring to a boil over high heat, let boil for 1 to 2 minutes to release scum, then dump the bones into a clean sink (or set a strainer in the sink). Rinse the scum off the bones. Scrub the pot then replace the bones. Add 12 cups water then bring to a boil over high heat; skim bits of scum that appear, then add the salt, rock sugar (or apple), and onion. Adjust the heat to simmer, uncovered, for 1 ½ hours.
While the broth cooks, peel and devein the shrimp, adding their shells to the simmering broth. Use a meat mallet to gently tap 3 or 4 times to crush each shrimp; the egg will cling better and create a faux fish egg effect. Season the shrimp with a pinch of each of salt. Beat the egg and yolk with 1 ½ teaspoons of fish sauce. Set aside.
Combine the paprika (or annatto) and oil in a small (8-inch) nonstick skillet. Set over medium-low heat. After the oil turns deep orange, 3 to 4 minutes, add the garlic. Let sizzle for about 45 seconds, stirring, then add the shrimp. Stir and cook for 2 minutes, until just cooked through. Pour in the egg, then stir to combine and coat. Cook for 1 to 2 minutes, until set and cooked. Transfer and scrape all the richness onto a plate, partially cover to cool, and set aside.
In a small bowl, combine the pickled leek, pickle brine, chile, and 2 tablespoons fish sauce. Set aside.
Cook the noodles in a pot of water until tender firm (use your judgement, not the package instructions, which often mislead), drain, flush with water and set aside to drain and cool.
When the broth is done, let it rest for 15 minutes, uncovered, to settle impurities and further concentrate. Strain it through a mesh strainer lined with muslin or paper towel, set over a medium (3-quart) pot. Season with about 1 ½ tablespoons fish sauce for a pleasant savory finish. You should net about 8 cups.
Over medium high heat, bring the broth to a simmer, slightly lower the heat to steady the heat and add the fish pieces. Let poach for 2 to 4 minutes (tilapia takes less time).
Meanwhile, put a handful of beans sprouts in each bowl. Top with the noodles, spreading it out to make a flat surface. Divide the shrimp among the bowls. When the fish is done, use a spider or slotted spoon to retrieve and divide the fish among the bowls. Tuck a pile of cucumber to one side of each bowl. Add some Vietnamese coriander to another corner. Add 1 tablespoon of the pickled leek and fish sauce mixture. Top with the green onion.
Return the broth to a boil, divide the broth among the bowls. Crown with fried shallot. Serve with extra pickled leek and fish sauce for adding more oomph to bowls. Present any remaining bean sprouts and cucumber along with the optional garnishes for diners to add at the table.
Notes
To make the broth in a pressure cooker, put the bones, salt, rock sure (or apple) and onion in a 6 quart pressure cooker or multicooker like the Instant Pot. Add 8 cups water, then cook on high pressure for 20 minutes. Turn off the heat and naturally depressurize for 20 minutes, then release pressure to strain and season the broth as usual. Miss nothing. SUBSCRIBE to my recipes, posts + newsletter!