Pour half the oil into a large, heavy-based frying pan and stir in the onion, raisins and pine nuts. Add the citrus rind, dill, fennel seeds and chilli, then place the pan over a very low heat. Bruise the garlic cloves with the side of a large knife and add to the pan. Cook, stirring occasionally, for 12–15 minutes until the onion is golden and caramelized. Add the wine and boil rapidly for 2 minutes.
Cook the pasta in a large saucepan of salted boiling water according to the packet instructions until al dente. Drain, reserving a ladleful of the cooking water.
Meanwhile, spread the breadcrumbs out on a large baking sheet and drizzle with the remaining oil. Toast in a preheated oven, 220°C (425°F), Gas Mark 7, for 4–5 minutes until golden brown.
Increase the heat under the frying pan to high, add the sardines and cook, stirring, for 1–2 minutes until the fish turns opaque. Toss in the pasta and stir until well combined. Add the reserved pasta cooking water and stir until the pasta is well coated and looks silky. Remove from the heat, then stir in the toasted breadcrumbs and the parsley. Serve immediately.