Fish and Leek Pie: The Ultimate Creamy Comfort Food Classic
Introduction
Creamy, flaky, and deeply satisfying, fish and leek pie is a British comfort food classic that brings together the tender sweetness of leeks with succulent chunks of fish in a luxurious white sauce — all crowned with a fluffy mash or golden pastry topping.
Whether you’re using fresh fish fillets, a smoked haddock mix, or leftover seafood, this dish is hearty, easy to make, and perfect for feeding a hungry family. It’s also a great way to eat more fish and sneak in some veg — especially leeks, which add subtle sweetness and melt-in-the-mouth texture.
In this guide, we’ll show you how to make a delicious fish and leek pie, share flavour twists, prep tips, nutritional information, freezer advice, and all the most commonly asked questions.
Classic Fish and Leek Pie Recipe
🧄 Ingredients (Serves 4–6)
For the filling:
- 500g mixed fish (e.g. cod, smoked haddock, salmon)
- 1 tbsp butter
- 2 medium leeks, trimmed, washed, and sliced
- 500ml milk
- 2 tbsp plain flour
- 2 tbsp butter (for roux)
- 1 tbsp chopped parsley
- Salt and black pepper to taste
- Optional: 100g cooked prawns or peas
For the topping:
- 750g potatoes, peeled and chopped
- 50ml milk
- 25g butter
- Salt to season
👩🍳 Method
1. Poach the fish
- Place the fish in a large pan with 500ml milk
- Bring to a gentle simmer and cook for 5–7 minutes until just cooked
- Remove fish with a slotted spoon, flake into large pieces, and set aside
- Reserve the milk for the sauce
2. Make the mash topping
- Boil potatoes until soft (12–15 minutes)
- Drain and mash with milk, butter, and salt
3. Cook the leeks
- In a frying pan, melt 1 tbsp butter
- Add sliced leeks and cook gently for 8–10 minutes until soft and translucent
4. Make the white sauce
- In a separate saucepan, melt 2 tbsp butter
- Stir in flour and cook for 1 minute
- Gradually whisk in the reserved poaching milk
- Stir until thickened and smooth
- Season with salt, pepper, and chopped parsley
5. Assemble the pie
- Combine poached fish, cooked leeks, and any extras (prawns/peas) in a baking dish
- Pour over the white sauce and mix gently
- Spoon mashed potato on top and spread evenly
- Use a fork to create ridges
6. Bake
- Bake at 200°C (180°C fan) for 25–30 minutes until golden and bubbling
Optional Add-ins & Variations
| Twist | How to Add It |
|---|---|
| Cheesy topping | Mix 50g grated cheddar into mash or sprinkle on top |
| Pastry-topped pie | Use puff pastry instead of mash (bake uncovered) |
| Smoked fish mix | Use more smoked haddock for stronger flavour |
| Mustard sauce | Stir 1 tsp Dijon or English mustard into white sauce |
| Veg boost | Add spinach, sweetcorn, or sautéed mushrooms |
| Herb upgrade | Try dill, chives, or tarragon for more aroma |
This recipe is wonderfully flexible — adjust it to suit your taste, dietary needs, or what you have in the fridge.
What’s the Best Fish to Use?
| Fish Type | Why It Works |
|---|---|
| Cod | Mild, flaky, family-friendly |
| Salmon | Rich, omega-3 boost |
| Smoked haddock | Traditional and packed with flavour |
| Pollock | Budget-friendly and sustainable |
| Prawns or scallops | Optional luxury additions |
Use one type or a mix. For a richer taste, include smoked fish — it balances beautifully with creamy leeks.
Can You Make Fish and Leek Pie in Advance?
Yes — it’s ideal for prepping ahead!
| Prep Method | How to Store |
|---|---|
| Unbaked pie | Cover and refrigerate for 24 hours max |
| Fully baked pie | Store in fridge for up to 3 days |
| Freeze for later | Cool completely, wrap well, freeze up to 3 months |
Reheating:
- From fridge: 180°C for 25 minutes until piping hot
- From frozen: Defrost overnight, then bake as above
Is Fish and Leek Pie Healthy?
It can be — especially when made with fresh fish, leeks, and a light sauce.
| Nutrient | Source | Benefit |
|---|---|---|
| Protein | Fish | Muscle support, satiety |
| Omega-3 fatty acids | Salmon, haddock | Heart and brain health |
| Fibre | Leeks, added veg | Gut health |
| Vitamin B12 | White fish, milk | Energy and red blood cell production |
| Calcium | Milk, butter, cheese | Bone strength |
To make it lighter, reduce butter, use low-fat milk, and skip the cheese topping.
What to Serve with Fish and Leek Pie
| Side Dish | Why It Pairs Well |
|---|---|
| Steamed green beans or peas | Adds crunch and colour |
| Roasted carrots or parsnips | Sweetness complements savoury pie |
| Simple salad | Lightens the richness |
| Buttered kale or spinach | Earthy greens balance the dish |
| Crusty bread | Perfect for soaking up sauce |
A drizzle of lemon juice or a spoon of tartare sauce also works as a nice contrast.
Can You Make It Dairy-Free?
Yes — with a few swaps:
- Use dairy-free butter in mash and roux
- Replace milk with oat or soy milk
- Omit cheese or use plant-based alternatives
- Ensure your pastry (if used) is dairy-free
Sustainability Tip
Use responsibly sourced fish by checking the Marine Stewardship Council (MSC) logo. Frozen fish mixes are often more sustainable and affordable — and they work perfectly in pies.
Conclusion
Fish and leek pie is everything a good comfort food dish should be — creamy, flaky, nourishing, and simple to make. The sweet leeks pair beautifully with fish, the mash adds a hearty topping, and the entire dish is pure cosiness in a casserole.
Customise it to suit your family, make it ahead, and freeze portions for rainy days. However you serve it, this classic pie is sure to become a favourite.
Top 10 Questions and Answers About Fish and Leek Pie
1. What fish is best for fish pie?
Cod, salmon, and smoked haddock are traditional. A mix offers great flavour and texture.
2. Can I use frozen fish?
Yes — defrost and drain before using to prevent excess liquid.
3. Do I need to cook the fish before baking the pie?
Poaching the fish first gives better texture and flavour in the sauce.
4. How do I stop the pie from being watery?
Drain cooked leeks and poached fish well. Thicken the white sauce properly.
5. Can I make fish pie without mash?
Yes — use puff pastry instead for a golden, flaky top.
6. Can I add cheese?
Yes — cheese in the mash or sprinkled on top adds a rich finish.
7. How long does fish pie keep in the fridge?
Up to 3 days in a sealed container. Reheat until piping hot.
8. Can I freeze fish and leek pie?
Absolutely — freeze before or after baking for up to 3 months.
9. What herbs go well with this pie?
Parsley, dill, chives, and thyme all complement the fish and leeks.
10. Can I make it gluten-free?
Yes — use gluten-free flour in the sauce and a GF pastry or mashed potato topping.