This isnt it.... but I know it was lemony. Try this one. But replace the potato with puff pastry...
* 25 g Butter
* 4 shallots finely chopped
* bulb Fennel finely chopped
* 250 ml Dry White Wine
* 250 ml Noilly Prat or dry vermouth
* 500 ml fish stock
* 500 ml Double cream
* 2 tablespoons wholegrain Mustard
* Sea Salt & freshly ground black pepper
* 800 g mix of white Fish Fillets such as cod, haddock, monkfish, coley
* 200 g raw peeled King Prawns
* Lemon Juice
* Few sprigs of Thyme
* Small handful of tarragon, flat leaf parsley chervil
For the topping
* 5 large Desiree Potatoes
* Milk for mashing
* Butter for mashing
* 2 large egg yolks
Method
* Heat the butter in a pan and sweat the shallots and fennel until soft. Add the wine and vermouth and reduce by half. Add the stock and bubble away again until reduced by half.
* Pour in the cream and boil until reduced to a sauce like consistency. Strain through a sieve, discarding the shallot and fennel. Stir in the mustard, check for seasoning then leave to cool.
* Meanwhile heat the oven to 180C/gas 4. Check the fish for any small bones, removing any with tweezers, then cut into 3cm chunks. Poach the fish in enough water to cover, with a squeeze of lemon juice and the thyme, until slightly undercooked. Remove the fish from the poaching liquid with a slotted spoon. Gently fold the prawns and fish into the sauce with a little extra lemon juice and chopped herbs. Transfer to an ovenproof baking dish.
For the topping
* Cook the potatoes in boiling salted water until tender, and mash with a little milk and butter until smooth. Beat in the egg yolks, then either pipe the mash over the filling or spoon it over for a more rustic finish.
* Bake the pie for about 20 minutes until bubbling and golden brown on top. Serve with buttered petit pois or spinach.
Notes And Tips