Fried Smelts with Bright Mustard Sauce

Kisu no Karashi Miso Soé

Preparation info

  • Difficulty


  • Serves


Appears in

An Ocean of Flavor: The Japanese Way with Fish and Seafood

An Ocean of Flavor

By Elizabeth Andoh

Published 1988

  • About

Parts of the American Midwest, particularly the Minneapolis-St. Paul region, are known for their spring smelt runs, and batter-frying seems to be the most common way to prepare the abundant catch. Here is a spicy new way to fix the tasty fish, one that the Japanese have been enjoying for centuries.


  • 8 small smelts, about 10-12 ounces
  • 1 teaspoon saké (Japanese rice wine)
  • 1 tablespoon soy sauce
  • tablespoons cornstarch


  • cup shiro miso (light fermented bean paste)
  • 1 tablespoon sugar
  • 2 tablespoons rice vinegar
  • 1 teaspoon soy sauce
  • 1 teaspoon hot mustard powder (preferably karashi)
  • 1 teaspoon cold water
  • 3-4 tablespoons dashi (basic sea stock)
  • vegetable oil for deep-frying


  1. Prepare the fish for frying: With the back of a knife, scrape off the scales. Remove the heads and trim off the dorsal (back) fins. Slit the belly cavities open to butterfly the fish, and remove the innards. With your fingers, carefully lift the backbones away from the flesh, cutting them off at the tails. Remove the small belly bones too, if you wish, though the Japanese don’t usually bother since they are fried very crisp in this dish. Rinse the butterflied fillets under cold water, then pat them dry.
  2. Mix the rice wine and soy sauce together, and dip the smelts into the mixture one at a time, making sure that both sides are moistened with the marinade.
  3. Pat the fillets dry, and then dust them lightly with the cornstarch. Set the fish aside while making the sauce; the fish will turn a reddish brown as the cornstarch absorbs the soy marinade.
  4. Make the bright mustard sauce: In a small glass or enamel-lined double boiler or saucepan, combine the bean paste, sugar, rice vinegar, and soy sauce. Stir with a wooden spoon to mix well, then cook over medium-high heat, stirring, until glossy, bubbly, and slightly thickened (about 1½minutes). Remove the pan from the heat.
  5. In a small bowl, mix the powdered mustard with the cold water, and stir to make a paste. Add the mustard to the bean sauce, and stir to incorporate well. Thin the sauce with sea stock until it has the consistency of heavy cream.
  6. Heat the oil in a deep-fryer or wok to about 370 degrees. Test it with a pinch of cornstarch moistened with soy sauce: It should sizzle on the surface of the oil immediately. Fry the smelts, two at a time, for slightly less than 2 minutes. The fish will be crisp and the oil bubbling around it will become quieter when the fish is cooked. Drain the fish on paper towels. If necessary, fried fish can be kept warm in a preheated 200-degree oven for up to 30 minutes.
  7. Serve the fish hot or at room temperature, one per person, napped with the bright mustard sauce as an appetizer or first course.