Salt the aubergine. Tumble the cubed aubergine into a colander set over a bowl. Sprinkle generously with salt and toss. Let it sit for 30 minutes. You'll see beads of moisture appear on the surface of the cubes—they'll look glossy and slightly damp. Rinse the cubes under cold water, then pat them bone-dry with a clean tea towel. This step is non-negotiable for the perfect texture.

Roast the vegetables. Preheat your oven to 220°C (200°C fan/gas 7). Spread the dried aubergine and the courgette half-moons on a large baking tray. Drizzle with 2 tablespoons of olive oil and a good pinch of salt. Toss with your hands to coat every piece. Roast for 20–25 minutes, turning halfway, until the edges are browned and the kitchen smells sweet and nutty. The aubergine should be soft and shrunken, the courgettes tender and flecked with brown. Set aside to cool slightly.

Start the sauce. While the vegetables roast, heat the remaining 2 tablespoons of olive oil in a large, heavy-based saucepan over a medium heat. Add the minced garlic and cook for 30 seconds—just until you can smell it, not a second longer. Stir in the oregano and chilli flakes, if using, until fragrant. Tip in the tinned tomatoes, crushing them with your hands or a wooden spoon, along with the tomato purée and sugar. Bring to a gentle simmer. You'll hear a soft, steady bubble—that's the sound of the sauce coming together. Let it cook, stirring occasionally, for 15 minutes, until it has thickened and darkened in colour. Taste it; it should be bright and savoury.

Boil the pasta. Bring a large pot of generously salted water to a rolling boil. Add the ziti and cook for 2 minutes less than the packet instructions. You want it very al dente—it will continue to cook in the oven. Drain the pasta, reserving a mugful of the starchy pasta water. The pasta should look pale and feel firm when you bite into it.

Make the ricotta mixture. In a small bowl, combine the ricotta, the egg, a generous pinch of salt, and a few cracks of black pepper. Stir until it is smooth and a pale, creamy colour. The smell is fresh and milky. Set aside.

Assemble the dish. Pour the tomato sauce into a large 23x33cm baking dish. Add the drained pasta and the roasted vegetables. Toss everything together until the sauce coats every piece of pasta and the vegetables are evenly distributed. If it looks a little dry, splash in a few tablespoons of the reserved pasta water. Dollop the ricotta mixture in small spoonfuls over the top, then scatter over the torn mozzarella and finally the grated Parmesan. The surface should look like a patchwork of white and gold.

Bake to golden perfection. Place the dish in the oven, which should still be at 220°C (200°C fan/gas 7). Bake for 25–30 minutes, until the cheese is deeply golden and bubbling, and the sauce is visibly simmering around the edges. You'll hear a happy, gentle sizzle. The top should be a landscape of brown and bronze, with a few darker spots of charred cheese—that's the good part. Let it rest on the counter for a full 10 minutes before serving. This is crucial. Scatter over the fresh basil just before you bring it to the table.