Place trimmed spinach and chopped spring onions in a large saucepan.

And stock to the saucepan and turn heat to medium high. Bring to a boil, and lower heat so mixture barely bubbles. Cook, stirring occasionally, until spinach is very tender, about 10 minutes.

Pour soup into a blender, in batches if necessary, and carefully purée. (Alternatively, use an immersion blender directly in the pan which is what I do when blending soups.) Return to pan, add cream, and over medium-low heat, reheat gently, stirring occasionally. When soup is hot, adjust seasoning, and serve.

Garnish with a few pieces of the chopped onions or a swirl of cream (optional).