Preheat oven to 200oC. Put drumsticks into a roasting pan or large ovenproof dish. Combine lemon rind, lemon juice, oil, garlic, salt and pepper in a jug. Pour over drumsticks and toss until well coated. Stand for 20 minutes. Roast drumsticks for 30-40 minutes or until golden, crisp and cooked through.
Meanwhile, put potatoes into a saucepan and cover with cold water. Place over a high heat and bring to the boil. Simmer for 10 minutes or until potatoes are tender. Drain and rinse under cold water. Transfer to a large bowl. When cold, add celery and dill. Combine sour cream and horseradish in a small bowl. Season with salt and pepper. Add dressing to salad just before serving. Toss until combined. Serve drumsticks with potato and celery salad.