Melt the butter in a saucepan and sweat the shallots on a low heat for a few minutes, without allowing them to colour.
Add the two cheeses and stir continuously, until melted. Add the double cream and stock and gently bring to the boil while stirring.
Pour into a blender and blitz until smooth. Pass through a sieve and check for seasoning.
To serve, pour the soup into warmed bowls, scatter with the asparagus, shallots, wild garlic, rocket cress and edible flowers, if using, and serve.