I love mussels, but they do present a few problems. We used to buy them live from the excellent tanks in Woolworths, which kept them in constant running water. Then they changed the tank design. I'm sure they're still perfectly safe and healthy, but the percentage of broken and open ones seems higher these days. They also seem to be very large.
What has had more impact on us is that Harvey used to put them in water under a very slowly running tap, then debeard them. After that they were simplicity itself to cook - into a big pot with good lid, along with a bit of wine, herbs, chopped garlic and shallots; cook over a high heat for a few minutes until they open, shaking them around; discard any that haven't opened; serve the rest in big bowls with lots of crusty French bread to mop up the juice.
These days I tend to get a bit lazier still and buy a big vacuum pack of them instead. They're very lightly cooked already, but still in their shells, with their juice. And they're all more or less the same size, not too big and muscle-y. I buy them on Tuesdays, so the shells and feet and stringy bits can go out in the rubbish that night. Then I turn them into a kind of delicious soupy stew.
To serve four (or really hungry three), you need:
Vacuum bag of mussels, chilli flakes, thyme leaves, garlic, shallots or red onion, good olive oil, dry white wine, two tins of plain chopped tomatoes - or better still, a large jar of Italian passata - and chopped flat-leaf parsley.
Carefully cut open the bag of mussels, pour all the liquid into a bowl, and either remove the top shell from each mussel or take them right out of the shells (easier to eat, but not as pretty).
In a large pot, soften the chopped shallots/onion, garlic, thyme, and a good pinch of chilli in a little olive oil over a gentle heat.
Add about two glasses of white wine (or more!) and reduce it a little over a high heat.
Turn down to medium heat, and add the passata or the chopped tomatoes with all their juice. Add the mussel liquid and a few empty shells to the pot. Simmer gently for a few minutes and remove the shells.
Add the mussels and cook gently for another five minutes. Check the flavour and add salt and black pepper to taste. (You don't need much salt - the mussel liquid is usually enough.)
Ladle into large wide bowls, and scatter chopped parsley generously over the top. Have your favourite bread warm and ready to mop it all up. These days I like a good ciabatta or French country loaf better than a baguette.