A classic, hearty, warming, wholesome seafood broth
Thinly slice medium 3 leeks and wash them very thoroughly. Cut 150g of smoked bacon into short strips and place in a deep pan with 40g of butter. Place over a moderate heat and let the bacon cook for a few minutes until the fat turns golden. Turn down the heat and add the leeks, then cover with a lid. Leave to cook for 20 minutes or so, until the leeks are soft and sweet. Check occasionally, so they don’t colour.
Have 750g of mussels ready, washed and checked, discarding any cracked or broken shells or any that don’t close instantly when tapped on the side of the sink. Put them in a large pot, pour in 100ml of white vermouth or white wine, then cover tightly with a lid and bring to the boil. Cook for a minute or two, then check their progress. If the mussels have opened, remove from the heat. If not, give them a minute or so longer.