Season and Brown the Chicken: In a medium bowl, toss the sliced chicken with cumin, coriander, garam masala, cayenne, salt, and flour until evenly coated. Heat 1 tablespoon of oil in a heavy-bottomed stock pot or Dutch oven over medium heat. Add the chicken pieces and cook, turning occasionally, until they’re browned on all sides and cooked through, about 6-8 minutes. Remove the chicken from the pot and set aside.
Sauté Aromatics and Vegetables: Add another tablespoon of oil to the same pot. Once shimmering, add chopped onion, celery, and carrot. Cook, stirring often, until the vegetables soften and become fragrant, about 5 minutes. Stir in the minced garlic and sauté for an additional minute until aromatic.
Bloom Spices and Make Roux: Push the vegetables to one side of the pot. Pour the remaining tablespoon of oil into the empty space and sprinkle garam masala, curry powder, and flour over the oil. Stir quickly to form a fragrant paste, cooking for about 1 minute to release the spices’ full aroma. Then, gradually add a small amount of chicken broth, stirring constantly to dissolve any lumps and create a smooth base.
Simmer the Soup: Pour in the rest of the chicken broth and bring the mixture to a gentle boil over medium-high heat. Add the uncooked rice, reduce heat to medium-low, and cover the pot partially. Let the soup simmer for 15 minutes, allowing the rice to cook and flavors to meld.
Add Apple and Chicken: Grate the peeled apple directly over the simmering soup to capture all its juices, then stir to incorporate. Return the cooked chicken to the pot and cook for an additional 5 minutes to heat through and blend flavors.
Finish with Coconut Milk: Lower the heat to gentle warmth and stir in the coconut milk thoroughly. Warm the soup through without boiling, then taste and adjust seasoning with salt and pepper as needed. Serve hot and enjoy!