Broccoli Fish Bake
Flaky white fish baked with broccoli and potatoes in creamy béchamel, finished with golden, buttery breadcrumbs. This is French gratin technique at its best, layers of good ingredients cooked slowly until everything melds together and the top goes crispy.
Ingredients
For the casserole
- 500 gr cod haddock, or pollock work well too
- 300 gr broccoli
- 2 waxy firm potatoes about 300g
- 50 gr breadcrumbs
- 30 gr unsalted butter
- squeeze lemon juice
For the béchamel
- 40 gr unsalted butter
- 40 gr plain flour
- 500 ml whole milk
- 1 tsp mustard Dijon
- 1 pinch nutmeg
- salt and black pepper
Instructions
1. Prep
- Preheat the oven to 190°C (170°C fan) and butter the dish. Cut the fish into 4cm chunks and season with salt, pepper and lemon. Cut the broccoli into even florets and slice the potatoes 3mm thick.
2. Blanch
- Boil a large pan of salted water. Blanch the potato slices 3–4 minutes until just softening, lift out. Blanch the broccoli 2–3 minutes, keeping some bite, and drain well.
3. Make the béchamel
- Melt the butter, whisk in the flour and cook 1 minute. Add the milk gradually, whisking, until it coats the back of a spoon, 5–7 minutes. Stir in the mustard, nutmeg, salt and white pepper. Keep it creamy but pourable.
4. Layer
- Potato slices on the bottom, then half the fish, half the broccoli, a third of the sauce. Repeat with potato, the rest of the fish and broccoli, another third of sauce. Top with remaining potato and the last of the sauce, covering everything.
5. Prepare the breadcrumb topping
- Toss the breadcrumbs with the melted butter and scatter loosely over the surface. Don't press down.
6. Bake
- Bake 30–35 minutes, until the crumbs are golden, the sauce bubbling, and the fish flakes easily. Check the centre is cooked through. Cover with foil for the first 20 minutes if browning too fast.
7. Rest and serve
- Let it sit 5–10 minutes before serving, with a green salad or crusty bread.
Notes
- Any firm white fish works. Avoid oily fish like salmon or mackerel.
- Homemade breadcrumbs from stale bread give a better, crunchier top.
- Swap the broccoli for cauliflower, or use both. Add peas for extra veg.
- Keeps 2 days in the fridge; reheat covered at 180°C for 20 minutes.
- For a richer version, replace 100ml milk with single cream.