Cut the squid (if using) into fine rings and set aside while you get on with the risotto.
Heat the stock or make up the concentrate/cube with boiling water, and keep the stock warm in a saucepan on the lowest heat.
Warm the two tablespoons oil in a large, heavy-based saucepan and soften the sliced spring onions for two minutes on a low heat. Keep stirring and don't let them burn.
Grate in the garlic and turn up the heat. Toss in the rice and turn it in the oil so it is slicked and shiny.
Pour in the red wine and let it bubble up over the rice.
Wearing disposable vinyl gloves, snip in the squid ink and carefully dunk the squeezed-out sachets into the separate pan of hot stock to get out any remaining ink.
Then add and keep adding ladlefuls of hot stock to the rice, letting one ladleful be absorbed before adding the next, stirring all the while.
When the rice has had 15 minutes, you can be less assiduous on the stirring front and get on with the squid, if you're using this.
In a frying pan, heat the remaining 2 teaspoons olive oil and the chilli until sizzling, then add the squid rings and cook, stirring or shaking the pan a little, for 3 minutes. Season with ground pepper, to taste.
By this time, the black risotto should be ready, so divide it between warmed shallow bowls or plates, top with chilli and squid, if using, and scatter with parsley.
Recipe from Nigella: Kitchen by Nigella Lawson (published by Chatto & Windus).