Start by making a basic stock. Peel the shrimps and put the shells into a saucepan with one chopped onion and one chopped tomato. Add cold water so that it almost covers the contents. Bring to the boil and allow to simmer for 15 minutes. Skim off during this period. Strain the stock.
Place the blue mussels and half the white wine in a warm paella pan or another wide frying pan. Pick out the mussels as they open. Taste the stock that is left in the pan. If it tastes good and is not too salty you can mix it with the shrimp stock.
Heat up some oil in the pan and fry the onion, carrot and swede while stirring until the vegetables start to change colour.
Add the rest of the white wine and allow it to boil down. Stir well; make sure you get everything that’s stuck to the bottom.
Add the celery root and potatoes. Add the shrimp stock while stirring the boiling vegetables. Make sure the pan does not boil dry.
When the potatoes start to soften, add the crab claws and allow them to sizzle until they are cooked, approximately 7 minutes.
Check if the vegetables are cooked – it’s perfect if some are just starting to collapse while others are still a little firm. Add the peeled shrimps and the prepared blue mussels.
Heat up and serve immediately.