Baked Pesto Fish with Vegetables

Preheat the oven and prep the vegetables

Preheat your oven to 200°C (180°C fan / 400°F). Add the sliced courgette, bell pepper, and red onion to a large baking tray, drizzle with 1 tbsp of the olive oil, and season generously with salt and pepper. Toss to coat, then spread everything out in a single layer so the vegetables roast rather than steam.

Roast the vegetables

Place the tray in the oven and roast for 10 minutes, until the vegetables are just beginning to soften and pick up a little colour at the edges. This head start ensures the veg and fish finish cooking at the same time.

Add the fish and pesto

Remove the tray from the oven and nestle the fish fillets on top of the vegetables, skin-side down if applicable. Season the fish with salt and pepper, then spoon the pesto evenly over the top of each fillet, spreading it into a thick, even layer. Drizzle the remaining 1 tbsp of olive oil over the vegetables.

Bake until cooked through

Return the tray to the oven and bake for a further 12–15 minutes, depending on the thickness of your fillets. The fish is done when it flakes easily with a fork and is opaque all the way through, with the pesto turning lightly golden on top.

Rest and serve

Let the tray rest for 1–2 minutes before serving — this helps the fish stay juicy and makes it easier to lift from the tray. Serve straight from the pan with crusty bread, rice, or a simple green salad.