1. Bring stock to boil in a saucepan on medium-high heat. Add celery, ginger and white pepper. Add the meat, a little at a time, stirring to break it up. Stir in cooked rice and fish sauce; simmer 5 to 7 minutes or until meat is cooked through.
2. Stir fry garlic in oil until golden brown and crisp. Drain on paper towels.
3. Ladle soup into bowls. Sprinkle with crisp garlic and fresh coriander leaves.