Place the aubergine cubes on a foil-lined baking tray. Drizzle with the olive oil, toss to coat and roast for 35 minutes, turning halfway through, until golden brown.
Cook the rigatoni in a large pan of boiling salted water for 2 minutes less than the time stated on the packet. Drain, reserving 80 ml (⅓ cup) of the cooking water.
Meanwhile, gently fry the garlic in the olive oil. Add the oregano and tomatoes, then simmer for 20 minutes. Crush the tomatoes with a spoon, stir in the reserved pasta water and cook for a further 5 minutes.
Add the pasta and roasted aubergine to the sauce and cook for another 5 minutes. Stir in the basil and season with black pepper.
Toast the bread, then crumble it into coarse breadcrumbs. Heat the olive oil in a small frying pan and gently cook the garlic. Add the breadcrumbs and cook until crisp and golden. Season with salt and pepper, then stir in the lemon zest and parsley.
Divide the pasta between serving bowls and top with pecorino shavings and the crispy breadcrumbs.