Preheat the oven to 200ºC. Trim the chicory and halve lengthways. Trim the celery and cut 10cm from the base, saving the top half for other cooking, and reserving the inner yellow leaves. Use a speed-peeler to remove the base and stringy outer edges, then slice lengthways 1cm thick. Place the chicory and celery in a roasting tray. Strip in the rosemary leaves, drizzle with a little olive oil, add a pinch of sea salt and black pepper and toss to coat. Roast for 25 minutes.
Remove the tray from the oven to a high heat on the hob. Squeeze over the orange juice, drizzle over the honey and vinegar, add a splash of water and bring to the boil. Give it a stir, then carefully transfer back to the oven for a final 10 minutes, or until nice and sticky and the liquid has reduced.
Toast the bread, halve the garlic clove and lightly rub the cut sides over the toasts, then place on your plates. Drizzle with a little extra virgin olive oil, then divide and tear over the burrata.
Delicately spoon over the roasted chicory and celery, and drizzle over that flavour-packed dressing. Pick over the parsley leaves and reserved celery leaves. Finely slice and scatter over a little chilli before serving, if you like.