Cod with a gremolata crust

Preheat the oven to 200ºC (400ºF, gas mark 6). Finely grate the zest and squeeze the juice from one of the lemons. Mix the zest with the breadcrumbs, parsley and garlic, and season to taste.

Place the cod fillets in a lightly oiled, large ovenproof dish. Then spread the mustard evenly over the top of the fish and sprinkle over the lemon juice. Arrange the tomatoes and courgette around the fish. Cut the remaining lemon into 4 wedges and put them into the dish too.

Spoon the breadcrumb mixture over the fish and press down lightly. Drizzle with the olive oil. Bake the fish for 25 minutes or until the topping is crisp.

Meanwhile, place the potatoes in a saucepan, cover with boiling water and add the saffron. Cook for 15–20 minutes or until tender. Drain the potatoes and mash with the milk. Season to taste. Serve with the saffron mash, tomatoes and courgettes.