Quick Recipe Version (TL;DR)
Quick Ingredients
- 1.2 kg floury potatoes (2 lb 10 oz), peeled and chopped
- 60 g butter + 120 ml whole milk for mash; salt, white pepper, pinch nutmeg
- 350 g undyed smoked haddock, skinless
- 350 g cod loin, skinless
- 200 g raw peeled king prawns
- 600 ml whole milk + 2 bay leaves + 1/2 onion + 6 peppercorns (for poaching)
- 50 g butter + 50 g plain flour (roux)
- 150 ml double cream
- 20 g fresh parsley, chopped
- 1 tsp Dijon mustard + 1 tsp lemon zest
- 120 g mature cheddar, grated
Do This
- 1. Heat oven to 200°C/180°C fan/400°F. Boil potatoes 15–18 min until tender; mash with 60 g butter, 120 ml milk, seasoning.
- 2. Simmer 600 ml milk with onion, bay, peppercorns. Add haddock and cod; poach 5 min, off heat 5 min. Lift out fish; flake in big chunks. Strain milk.
- 3. Make roux: melt 50 g butter, whisk in 50 g flour 2 min. Gradually whisk in hot poaching milk + 150 ml cream; simmer to thicken. Stir in mustard, lemon zest, most parsley; season.
- 4. Fold flaked fish and raw prawns into sauce (add 100 g frozen peas if you like).
- 5. Tip into a 2–2.5 L (2–2.6 qt) baking dish. Spoon mash on, seal edges, rough up surface; scatter cheddar.
- 6. Bake 25–30 min until bubbling and deeply golden. Rest 10 min.
- 7. Garnish with remaining parsley; serve with steamed greens or a lemon wedge.
Why You’ll Love This Recipe
- Comforting classic: silky parsley sauce, tender fish, and a golden, cheddar-topped mash.
- Balanced flavors: smoky haddock, sweet prawns, and mild cod in perfect harmony.
- Make-ahead friendly: assemble earlier in the day (or freeze) and bake when you’re ready.
- Family-sized and freezer-friendly—great for Sunday suppers or batch cooking.
Grocery List
- Produce: Potatoes, 1/2 onion, fresh flat-leaf parsley, lemon (for zest), optional frozen peas
- Dairy: Whole milk, double cream, butter, mature cheddar
- Pantry: Plain flour, Dijon mustard, bay leaves, whole peppercorns, fine salt, white pepper; Seafood from fishmonger: undyed smoked haddock, cod loin, raw peeled prawns
Full Ingredients
Potato Mash Lid
- 1.2 kg floury potatoes (Maris Piper, King Edward, or Yukon Gold), peeled and cut into 3 cm chunks
- 60 g unsalted butter
- 120 ml whole milk
- 1/2 tsp fine salt, plus more to taste
- 1/4 tsp ground white pepper
- Pinch of nutmeg (optional)
Fish and Parsley Sauce
- 350 g undyed smoked haddock, skinless
- 350 g cod loin, skinless
- 200 g raw peeled king prawns
- 600 ml whole milk
- 1/2 small onion, thick slice
- 2 bay leaves
- 6 whole peppercorns
- 50 g unsalted butter
- 50 g plain flour
- 150 ml double cream
- 1 tsp Dijon mustard
- 1 tsp finely grated lemon zest
- 20 g fresh flat-leaf parsley (about 1 cup loosely packed), finely chopped
- Fine salt and white pepper, to taste
- Optional: 100 g frozen peas (no need to thaw)
Topping
- 120 g mature cheddar, coarsely grated
- 1 tbsp butter, for dotting (optional)
Step-by-Step Instructions
Step 1: Heat the oven and prep the potatoes
Preheat the oven to 200°C/180°C fan/400°F. Place the peeled, chopped potatoes into a large pot, cover with cold water by 2–3 cm, and add a big pinch of salt. Bring to a gentle boil and cook for 15–18 minutes, until a knife slides in easily.
Step 2: Make a fluffy mash
Drain the potatoes well, then return them to the hot pot over low heat for 1 minute to steam off excess moisture. Mash until smooth. Beat in 60 g butter and 120 ml milk; season with 1/2 tsp salt, white pepper, and a pinch of nutmeg if using. The mash should be soft but not loose. Set aside with a lid to keep warm.
Step 3: Poach the fish in aromatic milk
In a wide saucepan, add 600 ml milk, the onion, bay leaves, and peppercorns. Bring to just below a simmer. Slide in the smoked haddock and cod. Poach at a bare simmer for 5 minutes, then remove from the heat and rest for 5 minutes. Lift out the fish with a slotted spoon, set on a plate, and flake into generous chunks (remove any skin or bones). Strain the poaching milk through a fine sieve into a jug—you should have about 600 ml; top up with extra milk if needed.
Step 4: Cook the parsley cream sauce
In a clean saucepan, melt 50 g butter over medium heat. Stir in 50 g flour and cook, stirring, for 2 minutes to make a blond roux. Gradually whisk in the hot poaching milk, then the 150 ml double cream. Simmer 3–4 minutes, whisking, until thick enough to coat the back of a spoon. Stir in the Dijon mustard, lemon zest, and most of the parsley (reserve a little for garnish). Season to taste with salt and white pepper—remember the smoked haddock adds saltiness.
Step 5: Fold in fish, prawns, and optional peas
Off the heat, gently fold the flaked haddock and cod into the sauce along with the raw prawns (and frozen peas if using). The prawns will cook through in the oven—keeping them raw now prevents them from becoming tough later.
Step 6: Assemble the pie with a sealed mash lid
Spoon the filling into a 2–2.5 litre (about 2–2.6 quart) ovenproof dish. Dollop the mash around the edges first to seal, then spread over the top. Use a fork to make ridges for extra crispness. Scatter the grated cheddar evenly and dot with a little butter if you like. Set the dish on a baking tray to catch any bubbles.
Step 7: Bake until bubbling and golden, then rest
Bake for 25–30 minutes, until the top is deeply golden and the filling is visibly bubbling at the edges. The internal temperature in the center should reach at least 75°C/167°F to ensure the prawns are cooked. Rest for 10 minutes before serving. Finish with the reserved parsley and serve with steamed greens or a lemon wedge.
Pro Tips
- Poach gently: keep the milk at a bare simmer so the fish stays tender and doesn’t break apart.
- Dry your potatoes: briefly steam-drying after draining prevents watery mash and helps the top crisp nicely.
- Seal the edges: spreading mash around the perimeter first prevents sauce from bubbling over the top.
- Texture matters: leave the fish in big, chunky flakes so you see and taste distinct pieces in every serving.
- Golden top: rough up the mash with a fork and use mature cheddar for maximum color and flavor.
Variations
- Add eggs: Fold 2–3 quartered hard-boiled eggs into the filling for a traditional touch.
- Swap the fish: Use salmon in place of cod, or add hot-smoked salmon for extra smokiness.
- Gluten-free: Make the sauce with a gluten-free flour blend or 30 g cornflour (starch) slurried into cold milk.
Storage & Make-Ahead
Assemble up to 24 hours ahead, cover, and refrigerate. Bake from chilled at 200°C/180°C fan/400°F for 30–35 minutes. Leftovers keep 2 days in the fridge; reheat covered at 180°C/160°C fan/350°F for 20–25 minutes until hot. To freeze, assemble but do not bake; wrap well and freeze up to 2 months. Bake from frozen at 180°C/160°C fan/350°F for 60–75 minutes (loosely tent with foil if browning too fast), or thaw overnight and bake 30–35 minutes. Cool leftovers quickly and reheat only once.
Nutrition (per serving)
Approximate: 720 kcal; Protein 42 g; Carbohydrates 45 g; Fat 38 g; Saturated fat 22 g; Fiber 4 g; Sodium 2.0 g. Values will vary with ingredient brands and any optional add-ins.
