Fish sauce plays many roles in the Southeast Asian pantry. The funky, fermented liquid enhances savory dishes, is fundamental in dipping sauces, and adds complexity to everything from soups to steamed vegetables.
Top-quality fish sauce begins with freshly caught fish, usually anchovies, which are layered with sea salt and packed into wooden barrels or ceramic vessels. They are left in the sun for between nine months and two years, during which time the fish break down, ferment, and exude a golden liquid. That liquid is strained into clear bottles and left to ferment for another few weeks. For second-rate fish sauce, salt water is poured into the drained barrels--the fish remnants still in them--and the fermentation starts up again.
Ancient Romans made their own version of fish sauce, which they called garum, by leaving salted mackerel innards in the sunshine to ferment for months. Garum production declined as the Roman Empire collapsed, and today it has practically disappeared. However, in the Campania region of modern Italy, fishermen continue to catch anchovies and then ferment the fish in brine in order to turn them into a condiment known as colatura di alici.
Asian grocery stores will likely carry several brands of fish sauce. Look for bottles that list only two ingredients: fish and salt. Additives like sugar and caramel color indicate lesser quality. The amber-colored liquid inside should be clear, without any cloudiness or sediment.
Nước Chấm, the classic Vietnamese dipping sauce, relies on the pungency of fish sauce. To make it, start with a splash of fish sauce, then sweeten with sugar, dilute with lime juice and vinegar (or water), and season with minced garlic and hot chile pepper. Nước Chấm is a simple sauce to make, but it tastes remarkably complex. Try it as a dipping sauce for spring rolls, as a marinade for grilled meat, or as a dressing for rice noodle salad. I like to do something that is, admittedly, a little less traditional. I steam delicate filets of sole in parchment packets with nước Chấm, combining a cornerstone of the Southeast Asian pantry with a cooking technique from Western Europe.
Filet of Sole Steamed in Nước Chấm
If you can't find or don't like sole, try using Pacific cod caught in Alaska, farmed Arctic char, or even shrimp.
1 tablespoon fish sauce
1½ teaspoons granulated sugar
2 tablespoons lime juice
2 tablespoons rice vinegar
2 - 3 small cloves garlic, minced
1 - 2 small hot red chiles, stemmed and minced
2 (4-ounce) filets of sole
2 - 4 small shiitake mushrooms, stemmed and sliced
1-inch piece of fresh ginger, peeled and finely grated
1 scallion, white and green parts, thinly sliced
2 tablespoons cilantro leaves, plus more for serving
Steamed rice, for serving
Heat the oven to 400°F.
In a small bowl, make the nước Chấm by stirring together the fish sauce, sugar, lime juice, vinegar, garlic, and chile.
Cut two approximately 16-inch-long pieces of parchment paper. Place 1 filet of sole in the center of each piece. Lightly season each filet with a tiny pinch of salt. Scatter the shiitake, ginger, scallion, and cilantro evenly over the fish. Gather the edges of the parchment, pulling them up and around each filet, then pour in the nước Chấm, dividing it evenly between the two parchment bundles. Tie each bundle tightly with twine and place on a rimmed baking sheet.
Bake until the fish is just barely opaque all the way through and the bundles have puffed with steam, 10 - 15 minutes, depending on the thickness of the filets. (It's okay to untie a bundle and poke the fish with a knife to see if it is cooked through--just be sure to return it to the oven, tightly tied, if it needs to cook for a few more minutes.)
Serve each bundle on a plate with steamed rice and a small handful of cilantro. Let your guests untie the twine at the table.