Heat the oil in a saucepan and fry the potato and garlic for 3-4 minutes, to soften.
Add the leeks and cook for a further few minutes.
Stir in the wine with the stock and cream then reduce the heat and simmer gently for 10-12 minutes, or until the potatoes are tender.
Using a hand blender, blend the soup until smooth and season to taste.
To serve, toast the bread on one side, under a hot grill, until golden. Turn over and lay the blue cheese on top. Return to the grill and cook until melted and golden.
Serve the cheese toast on top of the soup.