Heat the stock in a saucepan, then keep it on a low to medium heat during the rest of the cooking process. Bring a small frying pan to a medium heat. Add the pine nuts and shake the pan while they turn a golden colour. Empty out on to a small dish and leave to cool.
To make the sun-dried tomato cream, place all the ingredients in a small blender with half the cooled pine nuts and blitz to a smooth cream. If your blender is not powerful enough, you may need to pass the cream through a sieve to remove any tomato skins. Taste and adjust the flavour with sea salt and freshly ground black pepper, or a drop of lemon juice. Spoon the cream into a squeezy bottle or a piping bag, or into a small bowl, and set aside.
To pickle the radishes, put the vinegar, water and sugar into a small saucepan. Bring to the boil, then remove from the heat. Add the sliced radishes and leave to cool.
To make the risotto, bring a sauté pan to a medium heat. Add the olive oil and shallot and cook for a couple of minutes. Add the garlic and the rice and toss to coat them in the oil. Cook for two to three more minutes, then add the wine and cook until it has evaporated.
Start adding the stock a ladle at a time, stirring constantly and not adding more until the previous ladle has been absorbed. Towards the end of the cooking time (about 20 minutes), add the courgettes. When the risotto is fully cooked, stir in the rest of pine nuts.
To fry the red mullet, wash the fillets and pat dry. Put a large non-stick frying pan over a medium heat and add the olive oil. Lay the fish in the frying pan skin-side down and press down gently, using a spatula. Try not to overcook the fish, as its flesh will toughen – depending on the size of the fillets, two or three 3 minutes should be enough.
When the fish is cooked, transfer it to a plate and season with a little lemon juice and flaky sea salt. To serve, spoon some risotto into the middle of each plate, place two red mullet fillets on top, followed by a few pickled radishes, and drizzle the sun-dried tomato cream all around the plate.