Cut the onion into very fine cubes. Melt the butter in a very large saucepan, add the onion and sauté until translucent. In the meantime, wash the mussels, clean the shell and remove their whiskers. Important: It is essential to sort out mussels with broken shells and mussels that have already been opened before cooking, as they are no longer good or dead.
Add the stock cube and tomato paste to the onions in the saucepan and stir well until the stock cube is dissolved. Then add the cream and stir again. Simmer the cream sauce and season with a little salt and pepper, add the herbs.
Put the mussels in the saucepan with the cream sauce, stir and cover with a lid and simmer for 8 minutes on low heat until the mussels have opened. Important: It is essential to sort out the mussels that did not open during the steaming process, as they were already dead.
Cut a lemon into large cubes and serve with the mussels in the cream sauce.
A tip for eating: The mussel is opened completely and the mussel is detached from the shell with a small fork, but left in it. The opposite shell half can be removed. Then you use the shell with the mussel as a spoon for the cream sauce and drip some lemon juice onto each mussel.
The spicy cream sauce is then dipped and eaten with fresh, thinly cut slices of baguette.
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