Preheat your oven to 180°C fan/400°F/gas 6. Prep the sauce: Peel the garlic and ginger. Roughly chop them, place in a blender with the coconut milk, vegetable stock, curry powder, turmeric, tamari or soy, maple syrup and lime juice until smooth.
Prep the veg: Cut the sweet potato or squash into bite-sized pieces. Drain and rinse the black beans. Slice the sausages into bite-sized pieces. Slice the leek into 1–2cm rounds, washing thoroughly to remove any hidden sediment.
Combine the veg and sauce: Place the chopped sweet potato or squash, black beans, sliced sausages and leek into a large, deep oven dish. Pour the blended sauce over the vegetables and mix well.
Prepare the cauliflower: Cut the cauliflower head into four equal-sized steaks from top to bottom. Place the steaks and any smaller pieces, including the leaves (thinly sliced), on a separate baking tray. Coat with 2 tablespoons of oil, drizzle with 1 tablespoon of tamari, and sprinkle with salt.
Place the casserole dish and the tray of cauliflower in the oven. Bake for 30–40 minutes, or until the sweet potato or squash and cauliflower are tender and cooked through.
Chop the herbs: While the bake is in the oven, roughly chop your chosen fresh herb. Once baked, remove both the dish and tray from the oven. Carefully place the roasted cauliflower steaks on top of the curry bake in the casserole dish. Garnish with the chopped herbs and serve hot.