Wash and clean the spinach, removing the stems.
Chop the spinach leaves into small pieces.
Melt the butter in a pot. Add the flour and mix until you form a paste.
Add the clove, bay leaf, and onion.
Whisk in the milk, making sure to prevent any lumps.
Bring the mixture to a boil, lower the heat and let it simmer for a few minutes.
Remove the bay leaf and clove, and set aside.
Cook the chopped spinach in a pot for a minute or two, until tender.
Place the spinach into a food processor and finely chop it.
Place the sauce back into the heat. Add spinach and stir well for five minutes.