Start by heating your oven to 200°C (180°C fan). Remove any wilted outer cabbage leaves and cut the cabbage into four wedges. Drizzle the wedges with olive oil, then season with salt and black pepper.
Rub the oil evenly over the cabbage to help it caramelize during cooking. This step also prevents the cabbage from drying out while roasting.
Heat a large frying pan over high heat until it is very hot. Place the cabbage wedges cut‑side down in the pan.
Cook them for about 4 to 5 minutes until a deep golden char forms. Flip them and char the other side for another 4 to 5 minutes to create a smoky flavor.
Transfer the charred cabbage wedges to a roasting tray with the cut side facing up. Place the tray in the preheated oven.
Roast the cabbage for 30 to 35 minutes, or until it becomes tender while still holding its shape. The roasting process brings out the natural sweetness of cabbage.
While the cabbage roasts, melt the butter in a small saucepan over medium heat. Once melted, add the chilli oil and white miso paste.
Whisk the mixture gently until the miso fully blends into the butter and forms a smooth sauce. The goal is simply to mix the ingredients evenly.
Arrange the roasted cabbage wedges on a serving platter. Spoon the warm chilli miso butter sauce generously over the top.
Finish the dish by sprinkling sliced spring onions over the cabbage. Serve immediately while warm for the best flavor and texture.