Preheat the oven or BBQ to Gas Mark 8, 230°C (450°F). In a small bowl combine the cumin, turmeric, cinnamon, cayenne pepper, paprika, garlic powder, salt, pepper and rapeseed or olive oil.
Cut the potatoes into 2½ cm cubes. Add the cubed potatoes to the bowl and stir gently to coat in oil and spices. Spread the potatoes in a single layer on a lightly greased baking sheet. Bake for 20-25 minutes, or until the potatoes are golden brown, stirring once halfway through cooking time.
Before serving, toss with fresh coriander and re-season with salt and pepper, if needed.
