A comfort food classic levels up with spicy chorizo and crunchy sourdough topping.

Pasta is always a comfort food, so baking it ups the ante. If I'm going to do it I'm not willing to compromise on what makes it work. The topping has to be thick, and both cheesy and crunchy, so instead of using machine-smashed breadcrumbs, I tear sourdough bread into small pieces by hand for rustic effect (and real crunch), and mix it with both parmesan and mozzarella.

Below it, I want the familiarity of a tomato sauce along with the meat and spicy heat of chorizo. The filling is not swimming in sauce and even though I add water to the sauce, its purpose is to buy some time and let everything else cook together. By the time you're ready to add the pasta, the water will have cooked away and the sauce will be appropriately thick.

I use one of only two pasta shapes: the little cup-like orecchiette or, if they're in the cupboard, large spirals. Both capture and hold the sauce and bits of chorizo in a way that tubes – penne, ziti, rigatoni – never do.

Rather than pre-cook the pasta by boiling it, I simply immerse it in hot water – off the stove – for half an hour while I get the sauce ready. The difference is that it softens but is not completely cooked (its time in the oven will see to that, and give you properly cooked pasta instead of collapsing into mush) and it actually tastes better.

I've specified a weight for mozzarella, which you chop into little pieces. If you find the grape-sized baby (bambini) bocconcini they are wonderful here: you can just toss them in whole.

The baking dish I use, and which you can see in the photo, is 23cm by 14cm (9 x 5 inches) and 5cm (2 inches) deep. With a dish this size and the quantities below you could realistically, if modestly, feed 4 people if you had a decent salad alongside. In practice – in my kitchen, at least – it is served for two and there is a (mostly) polite battle for the leftovers. Better to scale up for larger numbers and, I can assure you, leftovers won't be a problem.

Chorizo pasta bake

Serves 2.

150g (1½ cups) orecchiette
2 slices sourdough bread (for 1½ cups crumbs)
25g (¼ cup) Parmesan cheese, finely grated
1 shallot or small onion, diced
1 clove garlic
100g (4oz) chorizo, cut into small pieces
200g (1 cup) canned diced tomatoes
1 tablespoon tomato paste
sea salt flakes
freshly ground black pepper
1 teaspoon butter, for greasing
200g (7oz) fresh mozzarella, chopped

Put the pasta in a large bowl and cover with water from a recently boiled kettle. Leave for 30 minutes, stirring occasionally, while you get on with the rest of the recipe.

Tear the bread into small pieces and place in a bowl. Add the Parmesan, mix together and set aside.

In a large, heavy based pan, warm the oil over medium heat and cook the shallot. When it starts to become translucent, grate in the clove of garlic and add the little pieces of chorizo. Cook until the chorizo starts to brown and crisp up.

Stir in the tomatoes, tomato paste and ½ cup water. Let it come up to a gentle bubble and cook for 5 minutes, until sightly thickened. Taste and season with salt and pepper. If your tomatoes are very acidic, add a pinch of sugar.

Set your oven to 220°C (425°F) and butter a baking dish.

Drain the pasta (or lift it out with a strainer) and add it to the sauce, mixing until well coated. Stir in three-quarters of the mozzarella and transfer to the baking dish. Sprinkle the bread and Parmesan mixture over the top and dot with the remaining pieces of mozzarella.

Bake for 20 minutes, until the top is golden brown and bubbling. Remove from the oven and let it rest for 5–10 minutes before serving.