Celeriac or celery root is an ugly little vegetable but tasty. It requires peeling and needs a sharp knife to cut it into slices – but all is worth it. When I lived in France it was often served grated with mayonnaise as an appetizer/starter. I decided to roast it with olive oil, rosemary and sage. Delicious as accompaniment to roast chicken or other meats. I cut the peeled celeriac into slices about 1/2 inch thick and then cut into triangles (like a pizza slice). Celeriac comes in various sizes so cut enough for however people you are catering for. Toss in olive oil, season with salt and freshly ground black pepper. Then tear up some rosemary and sage and sprinkle over. Cook in oven at 375 degrees for half an hour.