When the cold wind dies down and warm sunshine spreads over the sea, fishermen on the South Sea and West Sea think of spring's herald: the flounder that comes into season when the fishing ban ends.
Belonging to the order Pleuronectiformes and the family Pleuronectidae, the flounder has a distinctive look with both eyes set to one side. It lives close to the bottom and, in spring, its flesh fattens and the flavor deepens.
Records of flounder go back a long way. The first record is Uhae Euibo, written in 1803 by Kim Ryeo while he was exiled in Jinhae during the late Joseon era. In this encyclopedia-like book on seafood, academia interprets the expression "Dodaleo" as referring to today's "flounder." The theory that regional naming became fixed and settled into the current "flounder" has gained traction.
About 10 years later, in 1814, Jesan Eobo by Jeong Yak-jeon also contains a record that appears to refer to flounder. Jeong Yak-jeon recorded it as "beom-gajami," a name presumed to have been given based on the pattern on the fish's skin.
Smaller flounder can look like baby halibut. But the two are entirely different fish.
Both belong to the order "Pleuronectiformes," but halibut is in the "Paralichthyidae," while flounder is in the "Pleuronectidae."
The easiest way to tell them apart is the so-called "left halibut, right flounder." When viewed head-on, if the eyes are clustered on the left, it is halibut; if they are on the right, it is flounder or sole. Some even classify them by the number of syllables: two on the left for halibut (or neobchi), three on the right for flounder (or gajami).
However, even among halibut and sole, variants sometimes appear with eyes positioned on the opposite side.
Their appearance also differs. Sole are flat and small with an oval body, while halibut are broad. On average, flounder measure about 30 cm from head to tail, while halibut exceed 50 cm. Large halibut can top 1 m. Halibut also have large mouths with sharp teeth, but fish in the flounder family, including flounder, have small mouths and underdeveloped teeth. Halibut flesh is firm and chewy, making it good for sashimi, while flounder is soft and mild, making it better suited for grilling or soup.
Flounder is a high-protein, low-fat food that is good for dieting. It is known to help boost stamina thanks to its abundance of essential amino acids such as leucine and lysine.
Flounder is also a species selected this month (March) as the seafood of the month by the Ministry of Oceans and Fisheries. "Flounder mugwort soup," boiled with freshly sprouted mugwort in spring, is a signature delicacy of the southern coast. The fragrant mugwort and the mild taste of flounder combine to make it a favored health dish to beat spring fatigue.
There is one thing you must know before eating. Among the flounder we eat in spring as being in season, many are not true "flounder" but "shotted halibut." In particular, most of the fish used in flounder mugwort soup are shotted halibut. Because it is more common, widely distributed, and cheaper, it is often used as a soup ingredient.
☞ Flounder mugwort soup recipe
① Wash the mugwort and remove the thick stems.
② Slice the green onion on the bias, slice the chili thinly, and cut the radish into small squares.
③ Prep the flounder. Trim the fins with scissors. Clean out the innards and blood. Scrape the belly and back with a knife to remove the scales. Sprinkle with flour and wash to remove the slippery mucus. Cut into three or four pieces for easy eating.
④ Make the stock with anchovies, onion, green onion, and kelp. Using store-bought coin stock is fine.
⑤ When the broth develops, add the radish and bring to a rolling boil.
⑥ When the radish turns translucent, add the flounder pieces.
⑦ Season with soup soy sauce and minced garlic.
⑧ Boil for 10 more minutes, skimming off any foam. Add green onion and chili and boil 5 minutes more.
⑨ Add the well-washed mugwort and boil for 1 more minute to finish.