If you're buying raw middle-cut fish, gently cook it first. Baking or poaching works well. Once cooked, let it cool slightly, remove the skin and check very carefully for bones, then flake it.

You want around 700–800 g cooked fish flesh. If your 800 g refers to the raw weight including skin and bone, that's also fine. You'll simply get slightly fewer or smaller fish cakes.

Cook the onion in a non-stick pan with a splash of water or a very small amount of oil until softened.

Combine the flaked fish, onion, carrot, squeezed courgette, butter beans, oat crumbs, parsley, garlic, lemon zest and juice, paprika, pepper and cumin.

Add the egg and gently mix everything together.

The mixture should hold together when squeezed in your hand. If it's too wet, add another 1–2 tbsp blitzed oats. If it's unusually dry, add a spoonful of low-fat plain yoghurt.

Shape into 12 patties, roughly 2 cm thick.

If you have time, refrigerate them for 20–30 minutes before cooking. They'll hold together better.

Air fryer: my preference

Preheat to 190°C.

Lightly spray both sides of the fish cakes with oil.

Arrange them in a single layer without crowding. You'll probably need two batches.

Air fry for 12–16 minutes at 190°C, turning carefully after about 7–8 minutes.

They're ready when the outside is browned and crisp and the centre is piping hot.

Oven

Preheat to 200°C conventional / 190°C fan.

Place the fish cakes on a baking-paper-lined tray and lightly spray with oil.

Bake for 20–25 minutes, turning after about 12 minutes.

If you'd like more colour, give them another 2–3 minutes under the grill at the end.