Preheat the oven to 200°C, fan 180°C, gas 6. Heat the oil in a large pan over a medium heat. Add the pork and fry for 5 minutes, until brown and crisp. Stir in the grated courgettes and cook for 5 minutes, adding the fennel seeds, chillies, garlic and kale for the final 2 minutes. Season with freshly ground black pepper.
Meanwhile, bring a pan of water to the boil. Add the gnocchi and cook for 2 minutes. Drain, reserving 250ml of the cooking water.
Pour the cheese sauce into the pan with the pork mixture, then stir in the gnocchi, tomatoes and the reserved cooking water.
Pour the mixture into a 1.5-litre baking dish, top with the breadcrumbs and grated Cheddar and bake for 15-20 minutes until golden.