In a pot, melt half the butter then add the onion. Cook over a low heat, without browning.

Add the rice and toast it, mixing to avoid sticking. 

Cook slowly, adding one ladle of stock at a time and mixing until absorbed. Continue until the rice is cooked but not too soft (al dente). Remove from the heat then mix in the remaining butter, the grated Parmigiano Reggiano and salt to taste.

If possible, leave to rest overnight. When cool, take a handful of risotto and make a hole in the centre.

Place 4 mozzarella cubes in the hole then shape as a ball. Repeat until all the risotto has been used.

Roll each ball in breadcrumbs to coat then deep-fry until golden and the mozzarella centre has melted.

Cook’s notes:  Fior di latte mozzarella is a delicious cow’s milk mozzarella available from Woolworths. For a meaty alternative, add finely minced veal to the mozzarella in the centre of each ball.