Heat the oil in a large, heavy saucepan. Add the onion and cook over medium-low heat until it is translucent. Stir in the rice. Cook, stirring, about 5 minutes, until the rice is well coated with the oil and begins to whiten.
Have the stock barely simmering in another saucepan.
Add the wine to the rice, stir, then add 2 ladles of the hot stock.
Cook 3 minutes, stir in the cuttlefish mixture.
Continue adding stock, a couple of ladles at a time, stirring and adding more as the stock is absorbed by the rice.
Regulate the heat so the rice and stock cook at a steady simmer.
After about 15 minutes, the rice should have swelled and become somewhat tender but still a bit hard in the middle.
Continue adding stock for another few minutes, as needed. Until the rice is plump, offers only the slightest resistance to the bite, and there is just enough thickened, creamy, sauce-like broth to moisten the rice.
Season with salt and pepper to taste.