Keep your vegetable stock, whether homemade or from a stock cube, in a saucepan over a low simmer.
Heat the olive oil in a wide pan and fry the onion gently until softened and translucent.
Add the rice, increasing the heat slightly, and toast for a few minutes, stirring all the time, being careful that you do not brown the rice.
Add the white wine and stir until it has been absorbed by the rice.
Add a ladleful or two of the vegetable stock and stir frequently over a medium heat until most of the liquid has been absorbed, but do not let the rice dry out. Add another ladleful of stock and continue to cook in this manner – adding the stock gradually, stirring frequently – for around 15-20 minutes, until the rice is cooked but still al dente.
A minute or two before the rice is cooked, stir through the ‘nduja, and finish cooking.
Once the rice is cooked, stir through the butter, grated cheese, and scamorza, for about a minute, until well incorporated and the risotto has a creamy texture.
Pop a lid on the pan and leave to rest for a couple of minutes, before serving. Buon appetito!