Put the Camembert in an ovenproof dish. Make a few cuts in the top, then drizzle with the oil and sprinkle with the rosemary leaves.
Cover with foil and bake in a preheated oven, 200°C (400°F), Gas Mark 6, for 5–10 minutes until gooey.
Cut the French bread into chunky pieces and lightly toast until golden brown.
Sprinkle the walnuts over the cooked Camembert, drizzle with the honey and serve immediately with the toasted chunks of bread.