Select the spinach, wash well and drain.
Peel and chop the onion and garlic clove and sauté in 2 tablespoons of olive oil.
Add the spinach and cook for 5 minutes with the lid closed. Pour in clear soup and simmer for about 10 minutes.
Pluck basil leaves from stems (set a few aside for garnish) and add to soup.
Remove the rind from the cheese, crush with a fork and melt in the soup.
Puree everything with a hand blender. Season the spinach soup with salt, pepper and freshly grated nutmeg.
Remove the crusts from the toast, cut into cubes and toast in the remaining olive oil in a frying pan until golden brown. Pour the soup into warmed plates and garnish with the remaining basil leaves.
Offer the croutons with it.