Ingredients

  • 1 kg Maris Piper potatoes
  • 400 ml milk
  • 25 g butter plus extra for mashing
  • 25 g plain flour
  • 4 spring onions, finely sliced or any onion you have.
  • 320–400 g mixed fish pie mix (cod, salmon, smoked haddock)
  • 1 tsp Dijon mustard
  • Small bunch of chives, finely snipped
  • A handful of frozen petits pois
  • A handful of grated cheddar cheese
  • Salt and pepper to taste

Instructions

Heat oven to 200 °C/fan 180 °C/gas 6. Boil potatoes until tender, drain, then mash with a knob of butter and a splash of milk. Season with salt and pepper to taste.

In another pan, melt 25g of butter with onions and flour; cook for 1–2 minutes. Gradually whisk in milk, bring to the boil, and simmer until the sauce thickens. Stir in fish, mustard, chives and peas; transfer mixture to an ovenproof glass dish. Top with mashed potato, sprinkle over cheese, then bake 30-40 minutes until golden and bubbling.

Tips and variations

  • Swap in prawns or mussels alongside the cod and salmon for a seafood medley.
  • Stir in cooked spinach or diced asparagus for extra greens.
  • Top with sweet potato mash instead of regular potatoes for subtle sweetness and extra nutrients.
  • Add a panko breadcrumb layer under the mash for crunch, or sprinkle on top for the last 5 minutes.

Storage tips

  • Store cooled fish pie in the fridge for up to 3 days in an airtight glass container
  • Freeze portions (or the whole pie) for up to 3 months in airtight glass containers.
  • Label each package with contents and date to avoid forgotten freezer mysteries.
  • Fully defrost before reheating, then heat in the oven at 180 °C (fan 160 °C, gas mark 4) for 30 minutes, or microwave until the centre reaches 75 °C