Finely slice the leek and celery.
Put a wide, deep pot on a medium heat and add some olive oil and a knob of butter, along with the leek and celery.
Cook for about 10 minutes or until the vegetables are soft then flake in the smoked haddock and pour in the whiskey.
Set the pan alight and wait until the flames die down and the alcohol has evaporated
Add the mussels and double cream. Stir well, put the lid on the pan and cook for 4-5 minutes or until the mussels have all popped open – throw away any that stay closed.
Bubble the cooking liquor until it thickens
Roughly chop the parsley and add to the pot
Taste the sauce for seasoning and pour it all over the mussels. Scatter the celery leaves over and serve with bread or skinny chips.