Spray a large saucepan with low-calorie cooking spray and place over a medium to low heat.
Sauté the leeks and onions for 10 minutes, until soft but not browned.
Stir in the rice and then add the white wine vinegar. Stir until this has been absorbed.
Add the hot stock and stir well. Bring to the boil, then reduce the heat and leave to simmer for 15 minutes. You don't have to stir constantly, just check and give a quick stir every 5 minutes to make sure the rice doesn't stick to the pan.
After 15 minutes most of the liquid should have been absorbed, but there should be a little remaining. If it has dried out, add a splash of water.
Now, begin to stir rapidly for 4-5 minutes, until the remaining liquid has been absorbed and the risotto has a creamy consistency.
Add the spreadable cheese and grated Cheddar and stir until melted.
Season to taste with some salt and black pepper and serve!