Peel the onions and cut into chunks. Bring a pot with salty water to the boil and add the potatoes. Pour the Oldenburger Fullcream Milk and the Oldenburger Whipping Cream in a pot and let it simmer. Cut the fish filet into the desired portions and carefully make cuts in the skin. Wash the algae (glassworts) and pat dry. Roast the breadcrumbs in a hot pan until golden brown and set aside.
The Nut Butter and Cod
Heat the Oldenburger Butter in a pot at high heat. When the butter begins to simmer, the whey will separate from the fat. Skim the whey gradually off, using a skimmer. This will result in a clear butter. It turns brown after a few minutes and develops the desired nutty aroma. When the Oldenburger Butter has turned dark brown and the whey has been completely removed, throw a sieve with a cloth.
Take a tray and fill the nut butter in and heat it to 68 °C. When it has reached the temperature, place the cod on the tray and let it slowly cook for about 20 minutes.
The Potato Mousseline
Peel the cooked potatoes and press them through a potato press. Add the room tempered Oldenburger Butter plus the mixture of warm Oldenburger Fullcream Milk and Oldenburger Whipping Cream. Season with salt and nutmeg and mix it well. If you want it super soft, strain the puree through a sieve. Take 5 spoons of the mash and set aside.
The Black Sauce
Heat the Oldenburger Butter in a pot, add the onions and let it simmer for approx. 20 minutes medium heat. Pour in the ‘chipotle en adobo’ and the seafood fond and let it simmer for another 10 minutes. Put the mixture into a blender, add the ink and mix to a smooth consistency. Season with brown sugar. Pour the sauce into a squeeze bottle, this will help you to make nice dots on the plate.
Pour 5 spoons of potato mash and a handful of glassworts with some seafood fond into the blender and mix until smooth. Heat some butter in a pan, add seafood fond and put the rest of the glassworts in and fry them up.
The Final Touch
For serving, use a square food ring to bring the potato mousseline into shape and remove the food ring afterwards. Sprinkle some roasted breadcrumbs around if you like it more fancy.