Heat the oil in a wide, deep frying pan over a low heat and fry the guanciale or pancetta for 5-6 mins until crisp and golden. Remove to a bowl using a slotted spoon.

Turn the heat up to medium and cook the onion for 15 mins until completely softened. Add the garlic and cook for another 2-3 mins, then sprinkle in the black pepper, stirring well. Pour in the rice and toast in the onion and garlic mixture for 4-5 mins, stirring often.

Pour in the wine and let it bubble away completely, then slowly start adding the chicken stock, a ladleful at a time, stirring continuously. Wait until all the stock has been absorbed before adding the next ladleful. Once all the stock has been added, cook the risotto for 5-10 mins more until the rice is tender. Stir in the parmesan and guanciale and season well with salt and pepper. Leave to cool completely, then transfer to a lidded container and chill overnight.

Scoop the cold risotto into 18 equal balls, slightly larger than a golf ball. Working with one at a time, flatten a risotto ball in your hand and put a piece of mozzarella in the centre. Form into a rough ball again to enclose the cheese, then roll to neaten and seal. Repeat with the rest of the risotto balls.

Put the flour, egg and panko breadcrumbs in three separate, shallow bowls. Dip each stuffed risotto ball into the flour, followed by the egg and breadcrumbs until coated. Transfer to a tray and set aside. At this stage, the arancini can be frozen for up to three months. Freeze on the tray until solid, then transfer to freezerproof food bags.

Half-fill a large, heavy-based saucepan with vegetable oil and heat over medium-low until it reads 170C on a cooking thermometer, or until a piece of bread turns golden brown in the oil within 45 seconds. Lower the arancini into the oil and fry in batches for 5-6 mins, or until golden brown and melted in the centre (you may need to add another minute if frying from frozen). Set aside on a tray lined with kitchen paper, and season with sea salt. Serve warm. (If needed, they can be reheated in a low oven.)