In a saucepan over medium heat add a small glugg of olive oil.
Remove sausage from casing and drop in to hot pan. Use a potato masher to break up sausage into smaller pieces. Cook until pink is gone.
Add onions, carrots and celery into pan with sausage. Drop heat to low and cook for 5-10 minutes or until vegetables start to soften slightly. Add in thyme.
Pour in stock, add chicken and bring soup to a boil. Drop down to a simmer. Sprinkle in a pinch of salt and pepper and parsley.
Simmer for another 15-20 minutes to ensure vegetables soft.