Blend all ingredients in a high speed blender except for the baguette.
When smooth, transfer to a small saucepan.
Heat over a medium heat, constantly stirring, until it begins to thicken. This will take only a few minutes.
When the cheese is thick like melted cheese, remove from the heat.
Preheat the grill.
Spread the cheese over the baguette slices and place on a baking tray.
Grill for a few minutes, until the cheese starts to brown.
Serve with the soup immediately.