Mussels are one of my favs. if they are fresh and prepared in the right way, they will give you the real taste of the sea. However, they are very delicate and need to be treated with care because, as it happens very often with fish and seafood, overcooking is a very common mistake and will spoil the result.
If you want to have an excellent result in terms of both flavour and texture, follow these simple steps.
First of all, you need to clean them: usually you will find a bit of seaweed coming out of the shell: pull it off (this is probably the most tedious part of the process).
Discard all the broken shells; once done, put them in a colander and rinse.
Put them in a pan large enough to allow some extra room as the shells will open up and the overall volume will increase and add a splash of water (or white wine if you prefer). You can add some crushed garlic if you like it.
With the lid on, cook on medium heat and, when they start opening up, stir them with a wooden spoon to allow even cooking (put the lid back on afterwards).
Do not cook for more than 3-4 minutes after they start opening up, and discard all the shells that didn’t open. If not using immediately, keep the lid on (if too much steam escapes, it will make the mussels dry, you want them soft and moist!)
The mussels will release a lot of liquid which is packed with flavour: you just need to strain it before using it. Use a colander (or even better a conical strainer if you have one) lined with muslin (kitchen paper will do if you don’t have it but it’s a bit more hard work and it gets ripped quite easily). By doing that you will make sure that no sand or other impurities will find their way into your plate.