Coat a large saucepan generously with olive oil over medium heat. Add the onions and salt and sweat them until translucent, about 5 minutes. Bring the pan to a medium-high heat. Add the rice and cook for 3 to 4 minutes, letting the rice slightly stick to the bottom of the pan and scraping it off. It should also sound crackly.
Add the saffron to the hot chicken stock; the stock should turn bright yellow.
Add the wine to the pan until it covers the surface of the rice. Season with salt and cook over a medium-high heat, stirring continuously until the wine has absorbed into the rice. Add the saffron chicken stock to the pan until it covers the rice. Cook over a medium-high heat, stirring continuously until the stock has absorbed into the rice.
Repeat this process two more times with the hot saffron chicken stock. When the third addition of the stock has absorbed and the rice is very creamy, bite a couple grains of rice to be sure it is cooked perfectly. If it is still a little crunchy, add a little more stock and cook the rice for another couple of minutes. When the rice is cooked perfectly, remove it from the heat.