Cut the chicken in half (lengthwise) so they're thinner and will cook faster. Lightly coat with salt. Bring a large saucepan to a medium-high heat. Add butter and olive. Cook the chicken on each side until lightly golden and just cooked through. Remove form the saucepan and set aside to rest.
Reduce the heat to medium and in the same saucepan, add onion, carrots, garlic, ginger, and celery. Sauté for 5 minutes.
Add salt, five spice and white pepper. Sauté for another 5 minutes.
Add flour and sauté for 5 minutes or until the flour turns a golden brown on the base of the saucepan.
Pour in the chicken stock and chopped chili. Stir, ensuring the flour loosens from the base of the saucepan.
Add the sweet potato, vinegar and soy sauce. Boil on a high heat until the sweet potato is fork tender. Stirring occasionally.
Once tender, add chopped broccoli and cream. Boil for another 5 minutes or until the broccoli is tender but still retains a bite. Remove the soup from the heat.
Tear the chicken breasts into bite size pieces and add to the soup, with any remaining juices. Salt to taste and you're now ready to serve.
Garnish with some freshly grated parmesan and freshly ground black pepper.