Stir-fried Choy Sum with Deep Fried Thick Tofu is a stir-fry using Chinese greens, but it has a Japanese flavour. It contains a good amount of umami from a special dashi stock, and uses minimal oil. It’s a healthy side dish. You can use non-fried hard tofu instead of Deep Fried Thick Tofu if you want to go even healthier!
Stir-fried Choy Sum with Deep Fried Thick Tofu is simple but full of flavour. It’s a great side dish you can make when you want to add one little dish to your meal. If you double the quantity, you can even have it as a main dish.
‘Atsuage’ (厚揚げ) or ‘namaage‘ (生揚げ) is the name for Deep Fried Thick Tofu is called in Japanese. It is made in a similar way to aburaage and tofu puffs but atsuage is nothing like these.
Atsuage vs Aburaage vs Tofu Puffs
In my recipes, I often used aburaage, which is a deep fried thin tofu. Aburaage is a versatile ingredient in Japanese cooking. It can be added to simmered dishes, miso soup and takikomi gohan. The following are some of my recipes usingabraage:
- Snow Pea Leaves Warm Salad (Nibitashi)
- Layered Chicken and Chinese Cabbage (Hakata-style Simmered Cabbage)
- Hijiki Seaweed Salad
- Daikon and Aburaage Miso Soup
- Curry Udon
- Rice with White Radish (Daikon Takikomi Gohan)
- Gomoku Gohan (Japanese Mixed Rice)
You could say that atsuage is a thick version of aburaage because the method of making them are the same – i.e. fresh tofu is deep-fried without coating – no flour or cornflour/corn starch.
It’s just that the tofu is quite thick in the case of atsuage. Even after deep frying, the inside of atsuage retains the original soft texture of tofu unlike aburaage, which has a spongy texture inside.
For this very reason, I don’t call atsuage ‘tofu puffs’, which are more readily available at Asian grocery stores and some supermarkets. Tofu puffs are closer to aburaage as the inside of the puffs are spongy and do not resemble silky smooth tofu. And they come in small cubes or triangular pieces.
But for today’s dish, you can use tofu puffs if you cannot find atsuage. Alternatively, you can use a hard tofu. You need to stir-fry the hard tofu pieces a bit longer to seal the surface of the tofu and protect the soft inside.
Secret seasoning used in Stir-fried Choy Sum with Deep Fried Thick Tofu
Today’s stir-fry is made of just choy sum and atsuage. But for flavouring I used a secret seasoning called shiro dashi (白出汁), which translates to white dashi stock.
Shiro dashi is a seasoned dashi stock made of sake, mirin, light soy sauce, salt, bonito flakes and konbu (dried kelp). The ingredients are very similar to the dipping sauce for Tempura and cold noodles such as Zaru Soba and Sōmen.
But shiro dashi is usually made as a condensed dashi stock and you need to dilute it with water or hot water when using it. The ratio of shiro dashi to water depends on the type of dish you want to make. Sometimes you don’t even dilute the condensed shiro dashi, like today’s dish.
The good thing about shiro dashi is that you can add great flavour to the dish by just adding a tiny amount. You can add the typical Japanese flavour without simmering the ingredients with other seasonings in a large quantity of dashi.
I am hoping that I can introduce more dishes using shiro dashi in near future.
Store-bought Shiro Dashi vs Home-made Shiro Dashi
You can buy shiro dashi at Japanese grocery stores. Below is the store-bought shiro dashi pack that I used in today’s dish. On the side of the pack, it tells you how much water you need to dilute the shiro dashi depending on the type of dish you are going to make.
Shiro dashi is full of umami but it is a very salty and sweet liquid because it is condensed. As you can see in the recipe below, I only used ½ teaspoon of shiro dashi with a bit of soy sauce and that was sufficient.
When shiro dashi was first created, it was made with white soy sauce, which is a soy sauce that is almost transparent light amber in colour (close to the colour of rice wine vinegar) unlike normal blackish soy sauce.
Shiro dashi was the dashi stock with white soy sauce, hence it is called shiro (white) dashi. Even now, the traditional Japanese restaurants make shiro dashi with white soy sauce to retain the colour of the ingredients better.
You can make shiro dashi at home and it is not so difficult. The flavour of home-made shiro dashi can vary and may not be the same as the store-bought one, just as the flavourings of any dishes differ household by household.
How to Make Shiro Dashi at home
Unlike dashi stock where bonito flakes and konbu (dried kelp) are cooked in boiling water, shiro dashi is made by cooking bonito flakes and konbu in the typical Japanese seasonings – soy sauce, sake, mirin and salt.
A large amount of bonito flakes and konbu (dried kelp) are added to a small quantity of seasoning mixture and cooked for a while to extract umami from the bonito flakes and konbu.
Here is the photo of all the ingredients in the saucepan after cooking for 10 minutes. It looks like there is hardly any liquid left since the bonito flakes absorbed a lot of liquid. I got about 100ml/3.4oz of shiro dashi from this.
Filter the liquid through a sieve and collect the clear amber-coloured shiro dashi.
I added a recipe for how to make shiro dashi below the recipe for Stir-fried Choy Sum with Deep Fried Thick Tofu. Home-made shiro dashi keeps for about a month in the fridge.
Stir-fried Choy Sum with Deep Fried Thick Tofu is a very quick dish to make and it is tasty. It is a perfect side dish when you need one more dish to add.
It’s a stir-fry using Chinese greens but it has a Japanese flavour. It contains a good amount of umami from a special dashi stock, and uses minimal oil. Deep Fried Thick Tofu can be substituted to non-fried tofu if you prefer.
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 that can make up a complete meal. I hope it is of help to you.
- 100g/3.5oz choy sum , cut to 5cm/2" long pieces (note 1)
- 185g/6.5oz deep fried thick tofu (atsuage), cut to bite-size blocks (note 2)
- ½ tbsp sesame oil
- 1 tbsp sake
- ½ tbsp soy sauce
- ½ tsp condensed shiro dashi (note 3)
Add sesame oil to the frying pan and heat over high heat.
Add atsuage pieces and stir until the surface of the atsuage starts slightly browning (2-3 minutes).
Add the stem part pf the choy sum pieces and stir for 30 seconds. Then add the remaining choy sum and stir gently so that tofu pieces do not break.
Add the Seasoning ingredients and stir, ensuring that the vegetables are coated with the seasoning.
Serve while hot or at room temperature.
1. I like the texture of choy sum in stir-fried dishes as the stems stay crunchy. But you can use other Chinese green leaves such as Bock Choy or Chinese broccoli.
2. Atsuage is a thick tofu that is deep-fried without coating. You can find more details about assuage in the post. I cut an atsuage in half lengthwise, then cut them into 1.5-2cm/⅝-¾" thick slices, perpendicular to the first cut so that every piece has at least three fried sides.
3. Shiro dashi is a dashi stock seasoned with sake, mirin, light soy sauce and salt. I used a store-bought condensed shiro dashi, which you can buy at Japanese grocery stores. But you can also make shiro dashi at home. I added a Shiro Dashi Recipe below this recipe.
The secret seasoning called Shiro Dashi (白出汁) is a seasoned dashi stock that is made of sake, mirin, light soy sauce, salt, bonito flakes and konbu (kelp). It is very similar to the flavour of the dipping sauce for Tempura and cold noodles such as Zaru Soba and Sōmen. But Shiro Dashi is condensed and you are meant to use it by diluting it with water/boiling water.
- 150ml/5.1oz sake
- 100ml/3.4oz mirin
- 1 tbsp light soy sauce (note 2)
- ½ tsp salt
- 10 g bonito flake
- 5cm/2" x 10cm/4" konbu (dried kelp)
Add sake and mirin to a saucepan and bring it to a boil. Bring the heat down to low and simmer for 5 minutes to let the alcohol evaporate.
Add the remaining ingredients to the saucepan, bring down the heat to minimum so that it simmers extremely gently (almost like keeping the liquid warfor 5 minutes.
Turn the heat off and let it cool for 10 minutes.
Place two layers of muslin or kitchen paper over a sieve and place it over the top of the container.
Put the shiro dashi liquid with bonito/kelp through the sieve and collect clear liquid. Squeeze the muslin/kitchen paper to get the liquid out of the bonito flakes.
1. Store in a container/bottle. It keeps up to 1 month in the fridge.
Add water and bring it to a boil to make a clear soup.
Add soy sauce and water and cook simmered dishes.
Dilute 2 tsp shiro dashi with 3 tbsp water as the flavour base for Dashimaki Tamago (Japanese Rolled Omelette).
1. The final quantity you make depends on the evaporation rate and the type of bonito flakes you use. My bonito flakes were large pieces (larger than those you buy in a pack at the grocery stores/supermarket) and they absorbed quite a lot of liquid.
2. The original Shiro Dashi uses white soy sauce instead of light soy sauce. You can buy white soy sauce at Japanese grocery stores but I used light soy sauce instead. You could also use normal soy sauce.
The difference is the colour of the shiro dashi, which will then become the colour of the sauce for the dish you are going to make. I personally think that light soy sauce is quite OK since this is a home cooking recipe.
3. You can adjust the ratio of mirin and salt to make it sweeter or saltier to suit to your palate.