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Easy fish pie recipe with creamy mash

Name: Easy fish pie recipe with creamy mash
Prep time: 20 min
Cook time: 30 min
Total time: 50 min
Yield: 4-6
Cuisine: British
Ingredients: 1 lb white fish (cod or haddock); 1 cup frozen peas; 1 small onion, finely chopped; 2 cups milk (whole or 2%); 2 tbsp butter; 2 tbsp flour; 1 lb potatoes (russet or Yukon gold); 1/2 cup grated cheddar cheese; Salt and pepper to taste; Pinch of nutmeg

The first time I made fish pie, I was convinced it would be a disaster. I’d never cooked fish at home before, and the idea of mixing it with mashed potatoes seemed weird. But my grandma swore by it, so I gave it a shot. I accidentally overcooked the fish, under-seasoned the mash, and somehow burned the cheese on top. My family still ate it (bless them), but I knew I could do better. Now, after years of trial and error, it’s my go-to comfort food—warm, creamy, and forgiving, even when I mess up.

Recipe Card

Recipe Title	Easy fish pie recipe with creamy mash
Servings	4–6
Prep Time	20 mins
Cooking Time	30 mins
Calories	450 per serving

Ingredients

1 lb white fish (cod or haddock works best)
1 cup frozen peas
1 small onion, finely chopped
2 cups milk (whole or 2%)
2 tbsp butter
2 tbsp flour
1 lb potatoes (russet or Yukon gold)
1/2 cup grated cheddar cheese
Salt and pepper to taste
Pinch of nutmeg (trust me on this)

The first time I made this, I used tilapia because it was cheaper—big mistake. It fell apart into mush. Cod holds up way better. And don’t skip the nutmeg! I thought it was weird until I forgot it once, and the pie tasted flat. Also, frozen peas are a lifesaver. Fresh ones take forever, and canned peas? No thanks.

Directions

Peel and chop potatoes, boil until soft (about 15 mins).
While potatoes cook, sauté onions in butter until soft.
Add flour to onions, stir to make a roux, then slowly whisk in milk.
Add fish and peas to the sauce, simmer gently for 5 mins.
Drain potatoes, mash with a splash of milk and butter.
Layer fish mixture in a baking dish, top with mash, sprinkle cheese.
Bake at 375°F for 20–25 mins until golden and bubbly.

Here’s where I messed up: I once dumped all the milk into the roux at once, and it turned into lumpy glue. Now I add it slowly, whisking like my life depends on it. And don’t overbake the fish before assembling—it’ll dry out. Ask me how I know.

Another time, I got distracted and forgot the cheese. It was still edible, but let’s be real—cheese makes everything better. And if your mash is too thick, add a bit more milk. I’ve served cement-like mash before, and nobody thanked me for it.

This dish is perfect for lazy Sundays or when you need to feed a crowd. It reheats like a dream, and kids actually eat it (mine pick out the onions, but hey, win some, lose some). Next time, I might add a handful of spinach for extra greens.

Nutrition Info (per serving)

Calories	Carbs	Fat	Protein
450	35g	20g	30g

I was shocked how balanced this is—protein from the fish, carbs from the potatoes, and just enough fat to feel indulgent. For a lighter version, I’ve used skim milk and less cheese, but honestly, it’s not the same. If you’re gluten-free, cornstarch works instead of flour, but go easy—it thickens faster.

Ingredient Swaps

Ingredient	Substitution
Cod	Salmon (adds richness, but can be oily)
Cheddar cheese	Parmesan (crispier top, less creamy)
Peas	Corn or chopped carrots (texture change, but still good)

Salmon works, but it’s heavier—I’d use half salmon, half white fish. Parmesan gives a nice crunch, but my kids whined it wasn’t as gooey. Corn is fine, but carrots need extra cooking time. Once I tried broccoli, and it was a soggy mess. Lesson learned.

Tips

Don’t overcook the fish before baking—it’ll finish in the oven.
Season every layer (potatoes, sauce, fish) or it’ll taste bland.
Let it rest 5 mins after baking, or it’ll be lava-hot.
Use a fork to rough up the mash topping for extra crispiness.

I learned the hard way about seasoning. One bite of my first attempt tasted like cardboard, and my husband politely asked for the salt shaker. Now I taste as I go. And that resting tip? Yeah, I burned my mouth more than once diving in too soon.

FAQ

Can I make this ahead?
Totally! Assemble it, cover, and fridge it for up to a day. Add 10 mins to baking if it’s cold from the fridge. I’ve even frozen it, but the mash gets a little grainy.

Why is my sauce lumpy?
Probably added milk too fast or didn’t whisk enough. Strain it if it’s bad, or embrace the lumps—I’ve done both. A handheld blender can save it in a pinch.

Can I skip the cheese?
Sure, but why? Kidding. It’s fine without, but the top won’t brown as nicely. Try breadcrumbs for crunch instead.

That’s everything I know about making easy fish pie with creamy mash! Hope you give it a try. And if you mess it up, you’re in good company—I still do sometimes. Just call it “rustic” and serve it with a smile.