French onion soup with kombu seaweed

French onion soup with kombu seaweed

This French onion soup has an exotic touch thanks to the kombu seaweed which, besides having a good aroma, also contains many beneficial properties and it’s widely used in vegan menus.  It stands out for being rich in fibre, vitamins and minerals.

The recipe also includes shoyu, the first soy sauce to be consumed in the West, a sauce with a less intense flavour than other sauces because it contains a lower quantity of soy beans and salt.


  • 6 large onions, cut into thin semi-circles
  • 1 piece of kombu seaweed
  • 5 litres of water
  • Salt
  • Black pepper
  • Shoyu
  • 2 cloves of garlic
  • Extra virgin olive oil
  • 4 slices of bread
  • Chopped parsley
  • 3 mochi cubes (Mochi is a Japanese cake made of mochigome, a short-grain glutinous rice. The rice is hit until it becomes a paste and then it’s made into the desired shape).


  1. Heat a saucepan with a dash of extra virgin olive oil in it.
  2. Cook the onions with a little salt until they’re transparent.
  3. Cover the saucepan, turn the heat down and leave for at least 40 minutes. The onions have to have a very soft consistency. If they dry and start to stick to the bottom of the saucepan, add a little water.
  4. When they’re cooked, add the water and the kombu seaweed.
  5. Turn the heat up. When it comes to the boil, reduce to a slow heat and leave to cook for a further 20 minutes.  What you want is for the water to absorb the taste of the cooked onions.
  6. Take the kombu seaweed out and flavour the soup to your liking with a little shoyu and a little black pepper.
  7. Now grate the mochi and put it on top of the soup.
  8. In another pan, fry the bread and garlic until they’re very
  9. Put the bread and garlic onto a serviette to get rid of the excess extra virgin olive oil.
  10. And finally, serve the soup with the bread on top and a little chopped parsley.

And that’s it. As you’ve seen, it isn’t a very complicated recipe but it does require a bit of time because it’s necessary to get the texture of the onions right.

When you make it, apart from being very nutritious, you’ll notice that oriental touch which the kombu seaweed and the shoyu give it.

A taste which you’re very unlikely to be accustomed to but which we’re sure you’ll love.

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