Melt butter or oil in a large pot over medium-high heat. Cook the chicken until no longer pink. Add the onion, carrots, celery and apple, stir well and cook gently for 5-6 minutes.
Add the curry powder and cook for a few more minutes. Add the flour, mixing well, and cook for a few minutes to brown slightly.
Add the tomato sauce and the chicken broth. Blend well before bringing slowly to a boil. Reduce the heat. Add in the bay leaf, parsley, thyme and sugar. Stir and simmer for 30-45 minutes with a lid on the pot.
Remove bay leaf and add the lemon juice. You can add the rice to the soup or scoop rice into a bowl and serve the soup over the top. Salt and Pepper to taste and Enjoy!