Ingredients
Equipment
Frying Pan
Mixing bowl
Cooking Instructions
- Clean the king oyster mushrooms with a damp paper towel. Trim the tough ends, then use a fork to shred the thick stems into short, thin strands. Finely chop any large mushroom caps.
- Heat 1 tablespoon of butter in a large skillet over medium heat. Add the mushrooms and cook for approximately 5-7 minutes, stirring occasionally, until they soften and most of their released moisture evaporates.
- Add the finely diced onion and cook for another 3-4 minutes, until translucent. Stir in the soy sauce and crushed nori, then transfer the mushroom mixture to a plate.
- Melt the remaining 2 tablespoons of butter in a medium saucepan over medium-low heat. Add ⅓ cup flour and whisk continuously for approximately 2 minutes to form a smooth roux. Keep the mixture pale rather than allowing it to brown.
- Gradually add the warm milk, whisking continuously to prevent lumps. Cook for approximately 4-6 minutes, stirring frequently, until the béchamel becomes very thick and begins pulling away from the sides of the saucepan.
- Stir in the salt, white pepper, and nutmeg. Add the cooked mushroom mixture and combine thoroughly. The filling should be thick enough to hold its shape when gathered with a spoon.
- Transfer the filling to a shallow baking dish and spread it into an even layer. Cover the surface and refrigerate for at least 2 hours, until thoroughly chilled and firm enough to handle.
- Divide the chilled filling into 8 equal portions. With lightly floured hands, shape each portion into a short oval croquette. Work quickly to prevent the filling from becoming too soft.
- Arrange the flour, beaten eggs, and panko breadcrumbs in three separate shallow bowls. Coat each croquette lightly in flour, dip it into the beaten eggs, and cover it completely with panko. Press gently so the breadcrumbs adhere, paying particular attention to the ends.
- Pour vegetable oil into a deep, heavy-bottomed pan to a depth of approximately 2 inches. Heat to 350°F (175°C). Fry the croquettes in small batches for approximately 2-3 minutes, turning carefully, until evenly golden brown. Keep the oil near 350°F and avoid overcrowding the pan.
- Remove the croquettes with a slotted spoon and place them on a wire rack to drain. Allow them to rest for 2 minutes before serving.
- Arrange the hot croquettes alongside tomato salad or finely shredded cabbage and lemon wedges. Serve with vegetarian tonkatsu-style sauce if desired.
Nutrition
Notes
Choose king oyster mushrooms: Their thick, firm stems can be shredded into strands that resemble the texture of crab. Regular oyster mushrooms can also work, but they are softer and should be chopped rather than shredded.
Cook moisture out of the mushrooms: Excess liquid can loosen the béchamel filling and make the croquettes difficult to shape. Continue cooking the mushrooms until the skillet is nearly dry before combining them with the sauce.
Check the filling thickness: The béchamel must be considerably thicker than an ordinary white sauce. It should form a mound on the spoon rather than flowing freely. A loose filling is likely to leak during frying.
Chill before shaping: Refrigerating the filling for at least 2 hours helps the butter and starch firm up. If the mixture softens while shaping, return it to the refrigerator before breading.
Maintain the frying temperature: Oil that is too cool can produce greasy croquettes, while excessively hot oil may brown the breadcrumbs before the filling heats through. Fry in small batches and monitor the temperature with a thermometer.
Check sauces for vegetarian ingredients: Some Japanese-style sauces contain fish-based ingredients. Choose a vegetarian-labeled tonkatsu-style sauce, and use vegetarian breadcrumbs and other packaged ingredients when necessary.
Cook moisture out of the mushrooms: Excess liquid can loosen the béchamel filling and make the croquettes difficult to shape. Continue cooking the mushrooms until the skillet is nearly dry before combining them with the sauce.
Check the filling thickness: The béchamel must be considerably thicker than an ordinary white sauce. It should form a mound on the spoon rather than flowing freely. A loose filling is likely to leak during frying.
Chill before shaping: Refrigerating the filling for at least 2 hours helps the butter and starch firm up. If the mixture softens while shaping, return it to the refrigerator before breading.
Maintain the frying temperature: Oil that is too cool can produce greasy croquettes, while excessively hot oil may brown the breadcrumbs before the filling heats through. Fry in small batches and monitor the temperature with a thermometer.
Check sauces for vegetarian ingredients: Some Japanese-style sauces contain fish-based ingredients. Choose a vegetarian-labeled tonkatsu-style sauce, and use vegetarian breadcrumbs and other packaged ingredients when necessary.