|Prep time||30 minutes|
|Cooking time||30 minutes|
|Total time||1 hour|
1. Preheat the oven to 180C/350F/Gas Mark 4. Cut the leafy ends off the celery and reserve. Remove any tough strings from the outer stalks, and cut the sticks into 10cm lengths.
2. Put the stock or water, onion, bouquet garni and peppercorns into a pan. Bring to a boil and add some salt and the celery. Lower to a simmer, partially cover and poach until the celery is just tender - about 15 minutes. Remove celery from the poaching liqued and arrange in a lightly buttered gratin dish.
3. Put the strained poaching liquid into a clean pan and discard the onion, peppercorsn and bouquet garni. Simmer until reduced to about 100ml, remove from the hea and whisk in the creme fraiche, about two tablespoons of the chopped celery leaves, if you still have them, and the parsley. Check for seasoning and pour over the celery.
4. In a small bowl, mix the breadcrumbs and cheese, sprinkle over the gratin and bake until golden and bubbling, about 20 minutes.