Blanch the spinach in a lot of water. Drain and cut into small pieces.
Melt butter in a pan and sauté the sliced onions. Stop cooking before they brown and let cool.
Put the onions, spinach and 100 ml of milk in a blender and purée.
It should be the right texture and color after about 2 minutes. It should look like dark-green tea.
Transfer the purée into a pot and add the rest of the milk and the consomme cube and season with salt. Heat the soup over medium heat. Turn off the heat just before it starts to boil.
Serve the soup with heavy cream, black pepper, croutons or parmesan cheese if desired.
Story Behind this Recipe
I make this soup a lot. It's perfect for when you have too much spinach.
Don't let the onions brown or they will alter the color of the finished soup.
It's better to blanch the spinach since it is somewhat bitter. However, after blanching some of the nutrients will be lost in the water, so don't squeeze it out before adding it to the blender. You need some water to purée it anyway, so it's perfect – two birds with one stone.