The Ultimate Gluten Free Fish Pie


For the mash

  • 4 potatoes
  • 2 tbsp butter / dairy free spread
  • dash of milk (any milk works here, dairy free, lactose free etc)
  • 1-2 tsp mustard (wholegrain or dijon are my preferred)
  • salt and pepper
  • grated cheese, for the topping (dairy free cheese is fine too, I tend to use a regular parmesan as it's low FODMAP and has a lovely flavour)
  • handful of freshly chopped chives

For the fish

  • 1 packet of fish pie mix (haddock, salmon and cod) (mine was around 400g so you could just buy fish separately too)
  • 8-10 raw king prawns
  • 50 g smoked salmon

For the sauce

  • 250 ml milk (any milk works here, dairy free, lactose free etc)
  • 25 g gluten free plain flour
  • 25 g butter / dairy free spread
  • salt and pepper
  • handful of freshly chopped chives


  1. Preheat your oven to 160C.
  2. Start with the potatoes, peel, chop & boil for 15 - 20 minutes, until cooked and ready to mash.
  3. Mash your potatoes, I mash mine with a little milk (any type), butter (dairy free spread is fine), mustard (wholegrain or dijon are my preferred), salt and pepper. Put your mashed potato to one side till later.
  4. During or after you make your mashed potato, start on your fish. Place your fish into the dish you are going to make the fish pie in. Pour over your milk and place in the oven for about 10 minutes to gently poach and fill the milk with flavour.
  5. Once done, separate the fish and the milk (I usually just remove the fish from dish and put to one side). The milk will now be needed to make a white sauce.
  6. To create the sauce, add gluten free flour, butter or dairy free spread & the milk you poached the fish in to a saucepan. On a low/medium heat, keep stirring your mixture until it thickens. Add salt, pepper and freshly chopped chives to season. (You could also stir a little cheese or mustard to the sauce here, I tend not to but it's definitely an option that I can recommend)
  7. Return your fish to your oven proof dish. Mix it up a little so there will be different fish flavours in every mouthful.
  8. At this stage I then add some raw king prawns (frozen or fresh) and some think slices of smoked salmon. Both are optional but I really love a fishy fish pie!
  9. Drizzle over some of your white sauce (you don't need to use it all if you don't want to). You can mix your fish and sauce together before putting in the dish but there isn't any need to as it soaks through during cooking!
  • Spoon your mash over the top (I do this fairly messily and rough), make sure it's sealed at the edges.
  • Sprinkle some grated cheese on top (any dairy free cheese works, although I quite like a small amount of parmesan which is low FODMAP).
  • Cook in the oven for about 25 minutes at an increased temperature of 180C, until the top starts to go golden. I place my dish on a baking sheet incase the fish pie bubbles a bit! (If the top isn't golden enough for your liking just pop it under the grill for 5 minutes too - I do this with a lot of my cooking for a crispy top!)
  • Remove from the oven. Sprinkle some freshly chopped chives on top and serve with vegetables. Enjoy!