Bake the aubergines^ Preheat your oven to 190°C/Fan 170°C/Gas 5. Trim the green tops off the aubergines, then slice them into 6-8 wedges each. Arrange them in a shallow casserole dish or large ovenproof dish. Drizzle over 2 tbsp olive oil and season with a little salt and pepper. Slide into the oven and roast for 30 mins till the aubergines are golden brown.

Prepare the tomato sauce^ Meanwhile, peel and finely chop the red onion. Set a large pan on a medium-low heat then add the onion and 4 tbsp cold water. Season with salt and pepper and fry, stirring often, for 10 mins till starting to soften. If the onion starts to brown, turn the heat down a little and add a splash of water.

While the onion fries, peel and grate or crush the garlic. Drain the chickpeas. When the onion has cooked for 10 mins, add the garlic and 1 tsp dried oregano. Stir to mix, then tip in the tins of cherry tomatoes and the chickpeas. Add 2 tsp caster sugar (keep the rest for later) and 100ml cold water, stir and pop on a lid. Turn the heat up a little and bring to the boil, then turn the heat down and simmer for 10 mins. Stir now and then, till the sauce has thickened a little.

Take the sauce off the heat. Taste it and add a pinch more salt, pepper or sugar if needed. Pick the oregano leaves off their stems, roughly chop them and add most of them to the sauce.

Finish the gratin^ Take the aubergines out of the oven. Spoon the chickpea and tomato sauce over them. Drain the mozzarella balls, tear them into pieces and scatter them over the gratin, along with the breadcrumbs.

Bake the gratin^ Slide the dish back into the oven and bake for 20 mins till golden and bubbling. While the gratin bakes, toss the salad leaves with 1 tbsp olive oil and a pinch of salt and pepper.

Let the gratin cool in the dish for a few mins, then spoon the it onto warm plates. Garnish with the remaining oregano and serve with the salad leaves on the side.