Heat the oven to 200C/390F/gas mark 6.

Put the fennel wedges in a large bowl and mix with two tablespoons of oil, a quarter-teaspoon of salt and a good grind of pepper.

Spread out on an oven tray lined with greaseproof paper and roast for 30 minutes, until cooked through and golden-brown, then remove and set aside to cool.

Mix the peppers with a tablespoon of oil, an eighth of a teaspoon of salt and plenty of pepper, and spread out on a second oven tray lined with greaseproof paper.

Bake alongside the fennel for 25 minutes, until cooked through and brown, then remove and set aside to cool.

Turn down the oven to 180C/350F/gas mark 4. Heat the remaining tablespoon of oil in a large saute pan on a medium-high flame.

Fry the onion and garlic for 10 minutes, until soft and caramelised, then pour in the wine and let it bubble away for 10 minutes, until there is about 100ml of liquid left in the pan.

Add the tomatoes, orange skin and a quarter-teaspoon of salt, and cook for 10 minutes, until the tomatoes have disintegrated and the sauce is thick.

Stir in the fennel and peppers, as well as the olives, oregano and 120ml water, tip into a 20cm x 25cm gratin dish and set aside.

10 .Mix the topping ingredients in a large bowl, then scatter roughly over the top of the gratin.

Bake for 30 minutes, until the crumbs are golden-brown and crunchy, and serve hot.