So I did.
I used a very simple recipe, including the following ingredients:
Knob of butter
Splash of milk
Chunk of Boursin
4 spring onions, finely sliced
1 x pack frozen fish pie mix
1 tsp mustard
Two handfuls frozen mixed veg (peas/sweetcorn are preferable)
Handful of grated cheddar
I began by boiling the potatoes for 20 minutes before mashing with butter, milk and Boursin.
I then added the spring onions, flour and butter to a pan and heated until the butter had melted. Next, I poured in the milk, turned up the heat slightly and whisked until I had a lovely thick sauce.
Finally, I stirred in the mustard, fish and veg and allowed it to cook for 5-6 minutes before transferring to a dish and topping with the mash. At this stage, it is possible to chill and freeze the dish for another day. However, if cooking for dinner, sprinkle the pie with cheese and bake in preheated oven for 30 minutes or until golden and bubbling.
Honestly, I am not a great fan of fish - I eat it because it is supposedly healthy, not because I enjoy it. However, this fish pie is really rather yummy. There was a pleasing ratio of mash to sauce, which I think helped. Any less mash and I'm not sure I could have eaten it. But if you enjoy fish then this is definitely a great recipe, and a super simple one at that.