A classic simmered seafood dish, Simmered Flounder is so simple. Cooked in a sweet and salty sauce with ginger, Simmered Flounder goes so well with rice. The sauce only penetrates the surface of the flesh, so you can enjoy the flavour of the moist and plump flounder.
Simmered Flounder (Karei no Nitsuke) is probably one of the top 3 popular simmered fish dishes in Japan. It is also one of the easiest flounder recipes. The soft white flesh contains far less fat than other popular fish like salmon. Flounder is a perfect fish for those who need to watch their calorie intake.
In Japan, flounder is one of the fish that are given to little babies when they start eating solid food. It is also a perfect fish for the older people for the obvious reasons.
About Nitsuke (Simmered Fish)
As you all know, fish is central to Japanese food culture. There are many traditional ways of preparing and cooking fish – eating raw, steaming, blanching, etc. Simmering is one of the cooking methods for fish that existed long before sautéing and deep-frying.
Fish simmered in soy-based sauce is called ‘sakana no nitsuke’ (魚の煮付け) in Japanese, where ‘sakana’ (魚) is fish and ‘nitsuke’ (煮付け) is simmered dish. The word ‘no’ is equivalent to ‘of’.
Nitsuke is actually the same thing as ‘nimono’ (煮物). I introduced Nimono in my recipes, Simmered Pumpkin (Kabocha no Nimono) and Hijiki Seaweed Salad (Hijiki no Nomono). These are all simmered dishes.
But in general, the word ‘nitsuke’ is used for simmered fish while ‘nimono’ is used when vegetables are cooked with or without meat.
Since Nitsuke is a generic term for simmered fish, the name of the dish always uses with the name of the fish at the beginning, like today’s dish Karei no Nitsuke. ‘Karei’ (カレイ or 鰈) is flounder in Japanese.
Flounder is one of the flatfish species. In Sydney, I have only seen three kinds of flatfish – flounder, sole and halibut (very rare). But I read an article on the web that flounder can be used as a generic name for flatfish too.
The fish I used today was sold as flounder and I call it ‘karei’ in Japanese because the direction of the face is to the right. If my fish was facing to the left, I would have called it ‘hirame’ (ヒラメ or 平目). That is how Japanese people categorises the flatfish at a high-level.
Within this high-level group, each type of fish is named differently, starting with a representative word for the fish.
For example, the flounder that I used today probably belongs to ‘magarei’ (真ガレイ) in Japan, which implies the most representative type of flounder. The sound of ‘karei’ changes to ‘garei’ for easier pronunciation. The flounder with stone like patterns is called ‘ishigarei’ (石ガレイ), where ‘ishi’ means stone.
How to prepare Flounder for Nitsuke
Depending on the size of the flounder, you prepare the fish differently. But in all cases, you cook and serve the fish with the bones inside. There are few reasons for this: (1) The piece of fish retains the shape better when cooked, (2) The flesh around the bones is delicious.
Firstly, you need to remove the guts and scrape off the scales. The flounder I bought was already gutted but the scales were not cleaned. I use the back of the knife to remove the tiny scales.
If your flounder is very small and just right for one serving, you can cook and serve it whole. You may feel uncomfortable to see the fish on the plate with the head on. If so, you can cut the head off, although Japanese people leave it on.
For mid-size flounder of about 350-400g / 0.8-0.9lb, like my flounder in the recipe, remove the head and the tail, then cut it in half perpendicular to the back bone. Each piece becomes just right for one serving (about 150g / 5.3oz).
If the fish is much larger, you can cut the flounder into a few cutlets. Each cutlet will look like a narrow and long strip, with the bones in the middle.
The flounder sometimes comes with the eggs. Do not discard them – cook the fish with the eggs intact. They are delicious.
After cutting the fish into serving portions, make a cross incision on the right side (brown side) of the skin where the flesh is the thickest. This will make the fish cooked evenly. But if your flounder pieces are narrow long strips, you needn’t to do this.
How to cook Simmered Flounder (Karei no Nitsuke)
You need minimal ingredients to make Nitsuke.
- Flounder pieces prepared as per the previous section
- Shallots/scallions, cut into 5cm / 2” long pieces
- Thinly sliced ginger
- Simmering sauce that consists of water, cooking sake, mirin, soy sauce and sugar.
- Finely julienned ginger for garnish (optional)
Cooking is as simple as the ingredients list:
- Bring the sauce with the ginger to a boil.
- Put the flounder pieces in the sauce without overlapping, then place the shallots/scallions around the flounder pieces (top photo above).
- Place a drop lid (otoshi buta) on (bottom photo above), reduce the heat to medium to medium low and cook for about 5 minutes.
- Remove the drop lid. Using a spoon, scoop the sauce and pour it over the fish while continuing to cook for another few minutes. The sauce will become a bit thicker.
- Turn the heat off. Serve the fish with the julienned ginger on top and the cooked shallots/scallions on the side.
It takes only about 10 minutes to cook!
Note: It is important to use stiff julienned ginger pieces as a garnish on top of Nitsuke. Then you can pile the ginger pieces high on the fish, making the dish look more attractive. The stiff julienned ginger is called ‘harishōga’ ( 針生姜), which translates to needle ginger. If your julienned ginger pieces are limp, put them in ice water for a while to stiffen them up.
Suitable fish for Nitsuke
This technique of Nitsuke can be used to cook other kinds of fish too. Fish with white flesh is the best for Nitsuke and the fish is usually cooked with bones intact. The following are some of the fish names that you can substitute for the flounder:
- Leather jacket
- Ocean Perch
You can still make Nitsuke with fish that does not have white flesh and/or is oily, e.g. mackerel or sardines. But to counter the fishy smell and oiliness, more preparation of the fish is required and the sauce needs to be a bit thicker with a stronger flavour. I need to post a recipe one day for that.
Simmered Flounder can be made the day before. The flesh will absorb the sauce flavour more overnight and you might find that the fish has a bit stronger flavour.
You can also freeze Simmered Flounder for 1 month. Make sure the flounder is put in the sauce, then frozen so that the flesh does not dry. Thaw in the fridge before heating up.
A classic simmered seafood dish, Simmered Flounder is so simple. Cooked in a sweet and salty sauce with ginger, Simmered Flounder goes so well with rice. The sauce only penetrates the surface of the flesh and you can enjoy the flavour of the moist and plump flounder.
Don't forget to see the section 'MEAL IDEAS' below the recipe card! It gives you a list of dishes that I have already posted and this recipe so you can make up a complete meal. I hope it is of help to you.
- 1 whole flounder (about 350g / 0.8lb, note 1)
- 2 stems shallots/scallions cut into 5cm / 2” long pieces
- 1 tbsp ginger thinly sliced
- 1 tbsp ginger finely julienned (note 2)
If the flounder is not cleaned, remove the guts and scales. Cut the head and the tail off and discard. Cut the flounder in half, perpendicular to the back bone (note 1).
Make a cross incision on the right side of the fish (brown side) where the flesh is the thickest (see the photo in post). If you are using narrow strips of flounder cutlet, incision is not required.
Add all the Simmering Sauce ingredients to a shallow saucepan or a frying pan that can just fit the flounder pieces without overlapping.
Add the sliced ginger and bring it to a boil.
Put the flounder pieces in the sauce without overlapping, then place the shallots around the flounder pieces.
Place a drop lid (otoshi buta) on, reduce the heat to medium to medium low and cook for about 5 minutes.
Remove the drop lid. Using a spoon, scoop the sauce and pour over the fish while continuing to cook for another few minutes. The sauce will become a bit thicker.
Turn the heat off and transfer the fish to individual plates. Place the cooked shallots to the side of the fish and the julienned ginger on the centre of the fish.
1. Each flounder piece weighed about 150g / 5.3oz after preparing.
If your flounder is very large, cut the flounder into narrow strips, perpendicular to the backbone. If your flounder is very small, you can serve a whole fish per person.
If you want to, you can use a fillet without bones. In this case, place the fillets with skin side up.
2. If your julienned ginger pieces are limp, place them in ice water for a while. They should become stiff. Stiff julienned ginger is called ‘harishōga’ (針生姜), which translates to needle ginger. They look attractive when piled high and placed on the food.
3. Simmered Flounder can keep 1-2 days in the fridge. The flesh will absorb the sauce flavour more overnight and you might find that the fish has a bit stronger flavour.
You can also freeze Simmered Flounder for 1 month. Make sure that the flounder is put in the sauce, then frozen so that the flesh does not dry. Thaw in the fridge before heating up.
4. Nutrition per serving. It assumed 50% of the sauce is consumed but in reality, you don't drink the sauce served on the plate so the sodium and sugar would be lower.
serving: 244g calories: 196kcal fat: 3g (5%) saturated fat: 0.7g (3%) trans fat: 0.0g polyunsaturated fat: 0.6g monounsaturated fat: 0.8g cholesterol: 68mg (23%) sodium: 890mg (37%) potassium: 439mg (13%) carbohydrates: 17g (6%) dietary fibre: 1.5g (6%) sugar: 11g protein: 20g vitamin a: 1% vitamin c: 6% calcium: 4% iron: 5.2%