I made a curried butternut soup. It’s smooth but then there is a blast of ginger that is not pleasant - how do I fill that down ?

Ah, that has happened to me, too. I have found the best way to tone ginger down in a curried butternut soup is to add a bit of coconut milk. It works well with the flavors of the soup, and there is something about the extra fat in and the flavor of the coconut milk that neutralizes the bite that too much ginger can cause.

If that were not enough, I might blend a cup or so of the soup with a cup of white rice - using an immersion blender, and blending to a smooth puree - and adding that to the soup. ;o)