I was inspired to make okayu after seeing the dish shared on Candice Kumai’s instastories. She is a wellness journalist, serial cookbook author and all-round inspirational figure for health and wellbeing. Her photo of okayu looked as comforting as a hug, it sent up cravings for a similar warm bowl of nourishment.
Cauliflower Base
Okayu is Japanese-style rice porridge, like what congee is to the Chinese, kanji to the Indians and oatmeal to the British. Plain and soothing, okayu is popularly eaten as recovery food after long-term illness or in temples during fasting, and served with condiments such as umeboshi and pickles. Okayu is normally made with Japanese rice, but as I cannot tolerate grains well, I used cauliflower blended with dashi stock instead. In this dish I prepared the dashi, cauliflower and onsen egg sous-vide for best flavour. I understand not every one has a sous vide circulator, so I will provide the stove-top method in the recipe card as well.
Why Sous Vide Dashi
Kombu is the main ingredient of dashi, the workhorse stock used in Japanese cooking. Kombu is rich in glutamate – the source of umami – and can be enhanced synergistically with foods rich in ribonucleotides such as dried shiitake mushrooms and foods high in inosinitic acid such as katsuobushi (for non-vegetarians). In this dish I have used simple kombu dashi.
Read more about kombu on the resources page:
Experiments have shown that when making dashi, optimal glutamate extraction from kombu is obtained by steeping it at 65°C for one hour in a vacuum-sealed bag in a water bath. Instead of a vacuum bag I used a mason canning jar, which is more environmentally friendly and negates the messy problem of vacuum-sealing liquids. The flavour of this sous vide dashi was amazing, balanced, good body and not bitter. The type of water can also affect glutamate extraction from kombu; soft water, preferably less than 50mg calcium per litre, is considered the best. Fortunately where I stay in Singapore, tap water is fairly soft. If your tap water is very hard, use bottled filtered water.
The Onsen Egg or Coconut Sweet Potato Egg (vegan option)

Onsen egg (back) and vegan coconut sweet potato egg (front).
This is the first appearance of the real egg on this blog. Without getting into vegan debates, I’ll just mention these are free-range cage-free eggs from New Zealand (Barney’s barn eggs). I believe that when you’ve got an egg, you had better cook it right, and definitely no overcooked eggs. Onsen tamago is Japanese for “hot spring egg,” originally served at hot spring spas in Japan. The eggs are cooked naturally in the hot springs, resulting in a tender white and barely solidified yolk. At 63°C (145°C), the inner thick white of the egg starts to coagulate. At 65.5°C (150°F). the inner thick white becomes a tender solid and the yolk proteins start to thicken. At 70°C (158°F), the yolk becomes firm and set. Only at 82.2°C (180°F) does the outer thick white coagulate. As you can see the temperatures are quite precise; sous vide gives us precise control over time and temperature to achieve the desired consistency we want. It takes about 45 minutes for the water temperature to reach the centre of the egg, so any shorter amount of time means the yolk will be cooler and less set. Use this as a guide to your preferred doneness. I did not consume the eggs but prepared it for my family.
The vegan egg is made with coconut milk set with agar for the whites, and a blend of orange sweet potatoes, coconut milk, nutritional yeast, turmeric and sulphur-rich Indian black salt and asafoetida for the yolks. The whites were rather firm, so I would use less agar powder next time for a texture like onsen eggs.
Assorted Condiments
Okayu is meant to be a simple affair. I had to clean out the fridge of assorted veggies, so I served it with a rather extravagant array of stir-fried shimeji with ginger; beet, cabbage and mustard slaw; homemade kimchi; cucumbers and nori. Use any condiments you have on hand. Especially good with okayu are sour/salty items like pickles and umami-rich food like mushrooms and nori.


- Sous vide immerision circulator
- Large pot
- Vacuum bags
- Vacuum sealer
- Mason canning jar with lid
- Egg molds
- Blender
- 14 g (1/2 oz) kombu
- 946 ml (4 cups) soft water or filtered water
- 650 g (1 large head) cauliflower
- 4 free-range chicken eggs
- 200 ml (1 packet) full-fat coconut milk, divided into 170 ml + 30 ml
- 3/4 tsp agar powder (use less if you prefer softer "whites")
- 60 g (1/4 cup) sweet potato flesh (from 1 small baked orange sweet potato)
- 1 tbsp nutritional yeast flakes
- Dash of Indian black salt
- Pinch of asafoetida
- 227 g (1/2 pound) shimeiji mushrooms
- 1 tsp cold-pressed sesame oil
- 1 tbsp tamari
- 1 tbsp mirin
- 2 tsp ginger, grated
- 150 g pre-cooked or raw beetroot, julienned
- 100 g red cabbage, shaved
- 15 g (1/4 cup) parsley, chopped
- 2 tbsp lemon juice
- 1 tbsp homemade Dijon mustard
- Cucumber, sliced thinly
- Scallion, chopped finely
- Homemade kimchi
- Nori, cut into strips
- Shichimi togarashi
- Lightly wipe kombu sheets with a paper towel to remove any dust. The dry white powder on the surface of kombu contains much of the flavour – try not to wipe that off.
- Place kombu pieces in the jar. Fill jar with soft water, making sure the kombu is completely immersed but leaving 1 cm (1/2-inch) headspace. Wipe the rim of the jar thoroughly to ensure a good seal. Add lid and turn until snug.
- Place jar in an unheated water bath and add enough water to match the level of water in the jar. Using a sous vide circulator, heat water bath to 65°C (149°F). Once the desired temperature is reached, start timing. Cook the kombu for one hour.
- After one hour, remove the jar from the water bath. Strain the liquid into a bowl and set aside. The kombu pieces can be saved and reused to make secondary dashi. Fresh dashi can be stored in the refrigerator for a couple of days or in the freezer for 3 months.
- Tips: you can easily double or triple this recipe. Use 2 or 3 jars respectively.
- Alternatively, you can prepare the traditional way by cold-infusion. Soak kombu in water in a jar overnight and strain.
- Chop the cauliflower in florets, place into a vacuum bag and vacuum seal. Cook together with the dashi and onsen egg. When you remove the jar of dashi and egg, increase the temperature to 85°C (185°F) and cook another 20 minutes.
- Alternatively, you can steam the cauliflower for 5 minutes and set aside.
- Place the cooked cauliflower into a blender. Add 240 ml (1 cup) dashi stock and blend. Check the consistency. Add more dashi if you like it thinner.
- Once the water bath has reached 65°C (149°F), add it into the pot with the cauliflower and dashi jar and sous vide for one hour.
- Alternatively, you can poach the eggs.
- Add 170 ml coconut milk into a heavy-bottomed saucepan. Bring to a low simmer (at least 85°C/185°F), add in the agar powder and stir to dissolve. Simmer for 3 minutes, remove from heat and pour into egg molds. Place the mold into the freezer for 20 minutes to set. Once set, use a melon baller and scoop out to form a hollow for the yolk.
- To make the yolk, mash together the baked sweet potato, 30 ml coconut milk, nutritional yeast, Indian black salt and asafoetida. Fill the hollows with the mixture. Carefully unmold the eggs from the mold and place on a plate.
- In a heavy-bottomed saucepan, heat sesame oil on low heat. Add in the shimeiji mushrooms and stir to coat. Cover and cook for 3 minutes, then add in the ginger, tamari and mirin and cook for another 5 minutes until tender. Pour out into a bowl and set aside.
- In a large mixing bowl, combine all the ingredients. Use your hands and mix well. Set aside.
- Mise on place the ingredients you'd like to top your okayu with. Pour the cauliflower dashi porridge into bowls, then top with mushrooms, slaw, nori, cucumbers, kimchi and eggs.
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