Heat the oil in a saucepan over medium heat.
Add the onion, a pinch of salt and cook until soft – around five minutes.
Add the oregano and basil and cook for another minute.
Tip in the tin of plum tomatoes then fill half of the can with water and add this also to the pan.
Season with salt and pepper and add in the tablespoon of sugar.
Bring to the boil then simmer for around ten minutes.
In the meantime, toast the white bread and allow to cool.
Using a hand blender, blitz the soup until smooth.
Cut the cooled toast into shapes using cookie cutters then spread each piece with the olive tapenade.
Spoon the soup into bowls and season with cracked black pepper, top with the olive crouton and add a basil leaf to decorate.