Melt the spread in a large saucepan. Add the leeks and cook for 5 minutes, stirring now and then, until softened but not browned.
Cut the potatoes into thick slices and add to the pan with the vegetable stock and bay leaves. Season to taste with salt and freshly ground white pepper.
Cover with a lid, bring to the boil, then reduce the heat slightly. Simmer for 15 minutes or until the potatoes are very soft. Remove from the heat.
Stir the cream and Sheese into the hot soup, then discard the bay leaves. Blend with a stick blender until smooth.
Taste and adjust the seasoning if necessary.
Sprinkle with extra Sheese to serve.