Cut the turkey into small bite size pieces. Heat the oil in a large saucepan and fry the onion for 5 minutes until beginning to soften.
Stir in the garlic, courgette and pepper and fry for 1 minute.
Sprinkle over the flour and cook for 1 minute, stirring constantly.
Stir in the stock and bring gently to the boil. Add the turkey. Simmer for 30 minutes, then season to taste.
To make the croûtes, Heat the oil in a frying pan and add the sage leaves, cook until crisp then remove with a draining spoon and drain on kitchen paper.
Add the breads to the oil and fry until crisp and golden. Remove from the pan and drain on kitchen paper.
Serve the soup in warm bowls with the croûtes on the side or in the soup and top with the sage leaves.