Heat oil in a large saucepan or stockpot over medium-high heat. Add onion, garlic and bay leaves. Sauté 4-5 minutes until the onion is soft. Add half the carrot and half the celery, reserving the rest for later. Cook, stirring often for 3 minutes until vegetables start to soften. Add the chicken, breast side down and 2 1/2 litres (10 cups) of water.

Bring to the boil. Cover with a lid, reduce heat and simmer, uncovered on medium heat for 1 hour or until the chicken is cooked through. Remove the chicken to a plate. Strain the stock, discarding the vegetables.

Return the stock to the pan and bring to the boil. Add the leek, zucchini, cauliflower and reserved carrot and celery. Simmer for 4-5 minutes until vegetables are tender.

Meanwhile, shred the cooked chicken, discarding the skin and bones. Add the chicken to the soup, taste and season with salt and pepper. Stir through parsley and thyme. Serve with baguette.