Heat a Dutch oven over medium-high. Add bacon to pan; cook 4 minutes or until crisp. Remove bacon from pan with a slotted spoon, reserving 1 tablespoon drippings. Add truffle oil, onion, carrot, and celery to drippings in pan; sauté 3 minutes. Add thyme, mushrooms, and garlic; sauté 5 minutes. Add stock and 1 cup water; bring to a boil. Reduce heat, and simmer 8 minutes or until vegetables are tender. Add kale, salt, and pepper; cook 3 minutes. Stir in chicken and rice.
Combine half-and-half and flour in bowl, stirring with a whisk. Stir into soup; cook 2 minutes or until thickened. Top with bacon.