Cao lầu: Hội An's noodle dish

Cao lầu is a noodle dish from the old town of Hội An in Central Vietnam, made with thick, chewy noodles, slices of seasoned pork, fresh greens and herbs, crunchy fried croutons and only a small amount of rich sauce. It's famous partly because the noodles are so tied to Hội An that most people say real cao lầu can't be made anywhere else.

What makes cao lầu special

• The noodles. They're firm, springy and a little rough, closer to udon than to the slippery rice noodles in phở. They have a slightly yellowish or brownish tint.
• The local story. Tradition holds that authentic cao lầu noodles are made with water from a particular old well in Hội An, called Bá Lễ, and soaked in lye water made from wood ash. Accounts vary in detail, and few home cooks can reproduce it, which is part of the dish's mystique.
• Very little liquid. Like mì Quảng, the bowl has just a few spoonfuls of sauce, not a broth.
• Crunch. Squares of fried noodle dough, like croutons, go on top.

The origin is often linked to Hội An's history as a trading port with Japanese and Chinese merchants, and you'll hear people compare the noodles to udon and the pork to Chinese char siu. Historians don't agree on a single origin, so treat any neat origin story with some caution.

Ingredients (serves 4)

For the pork:

• 1½ lb (about 680 g) pork shoulder or loin, in one or two pieces

For the marinade:

• 2 tablespoons soy sauce
• 1 tablespoon fish sauce
• 1 tablespoon sugar
• 1 teaspoon five-spice powder
• 3 cloves garlic, minced
• 2 shallots, minced

For braising:

• 1 tablespoon neutral oil
• 1½ cups (360 ml) water or pork stock

For the bowls:

• 1 lb (450 g) dried cao lầu noodles, or thick fresh or frozen udon as a substitute
• 12 square wonton wrappers, cut into quarters, for croutons
• Oil for frying
• Lettuce, mint, Thai basil, Vietnamese coriander (rau răm) and bean sprouts
• Lime wedges and sliced chili or chili sauce

Allergens: soy sauce (soy, often wheat), fish sauce, wheat (udon and wonton wrappers) and possibly egg in wonton wrappers. Check labels.

Steps

1. Marinate the pork. Mix the soy sauce, fish sauce, sugar, five-spice, garlic and shallots. Rub it over the pork and marinate at least 1 hour, or overnight in the fridge.

1. Brown the pork. Heat the oil in a heavy pot over medium-high heat. Scrape off excess marinade, save it, and brown the pork on all sides, about 6 to 8 minutes.

1. Braise. Add the saved marinade and the water or stock. Cover and simmer on low for 45 minutes to 1 hour, turning occasionally, until the pork is tender but still sliceable.

1. Reduce the sauce. Remove the pork and let it rest. Boil the braising liquid until it's reduced to about ¾ cup (180 ml) and slightly syrupy. Taste and adjust with a splash of fish sauce or sugar.

1. Make the croutons. Heat 1 inch (2.5 cm) of oil to about 350°F (175°C). Fry the wonton squares in batches for 30 to 60 seconds until golden and puffed. Drain on paper towels.

1. Cook the noodles. Cook dried cao lầu noodles according to the package, or heat udon for 1 to 2 minutes in boiling water. Drain well.

1. Build the bowls. Put a handful of lettuce and herbs in each bowl. Add noodles, then thin slices of pork. Spoon 2 to 3 tablespoons of sauce over each bowl.

1. Finish. Top with croutons and bean sprouts, and serve with lime and chili.

How to eat it

Toss everything together so the sauce coats the noodles, the greens soften a little and the croutons are spread through. Add lime for brightness. Some people like a spoon of chili jam, which is common in Hội An.

About the substitutes

Udon is the most common stand-in because its chewiness is close, but it's softer and smoother than real cao lầu. Some Asian grocery stores carry dried noodles labeled "cao lầu," which get closer in texture. Either way, the pork, sauce, herbs and croutons carry most of the flavor at home.

Cao lầu vs mì Quảng

Both come from the same part of Central Vietnam, and both use little liquid. The main differences: mì Quảng uses rice noodles, turmeric, shrimp and peanuts, while cao lầu focuses on pork, wheat-like chewy noodles and croutons. If you're exploring Vietnamese soups and noodles beyond phở, making both side by side is a good lesson in Central cooking.

Reduce the braising liquid until it coats a spoon; that small, concentrated sauce is what holds the bowl together.