Bring a large pot of generously salted water to a rolling boil. The water should taste like the sea. Add your pasta and cook for 2 minutes less than the package instructions suggest—it needs to be very al dente, as it will continue cooking in the oven. Drain, reserving about a cup of the starchy pasta water. The pasta should look matte and feel firm to the bite.

While the pasta cooks, build your sauce. In a large, heavy-based saucepan or Dutch oven, warm the olive oil over a medium heat. Add the diced onion and cook for 8-10 minutes, stirring occasionally, until it turns translucent and the edges begin to catch a pale gold. You should hear a gentle, steady sizzle. The smell will turn sweet and mellow.

Add the garlic, oregano, and chilli flakes. Stir constantly for one minute, until the garlic is fragrant but not coloured—the moment it releases its perfume, you're ready for the next step. The kitchen will smell intensely of that warm, spicy aroma.

Pour in the crushed tomatoes and tomato purée. Stir well, then add the sugar, a generous pinch of salt, and a few grinds of black pepper. Bring the sauce to a gentle simmer—it should just be lazily bubbling, not boiling furiously. Reduce the heat to low and let it cook uncovered for 20 minutes, stirring every so often. The sauce will thicken, darken to a deeper red, and smell rich and concentrated. If it looks too thick, stir in a splash of the reserved pasta water.

In a medium bowl, combine the ricotta, beaten egg, and half the grated Parmesan. Season with a pinch of salt and pepper. Stir until smooth and homogenous. The mixture will be thick, pale, and slightly glossy from the egg.

Preheat your oven to 190°C (170°C fan). Taste the sauce and adjust the seasoning—it should be robust and slightly spicy. Remove the pot from the heat. Add the drained pasta and the ricotta mixture to the sauce. Stir gently but thoroughly. The sauce will cling to the pasta, and the ricotta will create creamy streaks throughout. You'll see a beautiful, chunky, rustic sauce.

Transfer the pasta mixture to a large baking dish (about 30x20cm). Spread it into an even layer. Dot the top with the torn mozzarella pieces, then sprinkle over the remaining Parmesan. The top should look patchy with white and pale yellow cheese.

Bake on the middle shelf for 25-30 minutes. Check at the 20-minute mark. You're looking for the sauce to be bubbling enthusiastically at the edges and the cheese on top to be melted and turning a deep, golden brown in spots. The smell coming from the oven will be incredible—a mix of baked tomatoes, toasted cheese, and chilli. Let it rest on the counter for 5-10 minutes before serving. This allows the sauce to settle and prevents it from being too runny.