Mulligatawny Soup

3 Tablespoons Butter
1 Tablespoon Vegetable Oil
1 large Onion, chopped
2 Stalks celery, sliced thinly
3 Carrots, diced
1 1/2 Tablespoons Curry powder
2 Tablespoons All-purpose flour
5 cups Chicken stock
2 Tablespoons Long grain white rice
2 Tomatoes; peeled & chopped
8 ounces Chicken; cooked & diced
1 small Apple; cooked, peeled, cored & diced
Salt to taste
Fresh celery leaves
Heat butter and oil in a saucepan. Add onion, celery and carrots; cook gently 5 minutes. Stir in Curry Powder and flour and cook 1 minute. Stir in stock and bring to a boil; add rice and stir well. Cover and simmer 20 minutes, stirring occasionally. Add tomatoes, chicken, apple and salt. Cover again and simmer 15 minutes. Garnish with celery leaves and carrot strip, if desired, and serve hot.