Preheat a fan-forced oven to 200°C/400°F/Gas Mark 6.
Spread sweet potato out onto a baking tray and drizzle with half of the oil. Place into the oven and cook for 20 minutes until golden and soft.
Heat the remaining oil in a medium skillet. Add leek and mushrooms. Cook for 2 minutes, until softened. Add kale and cook for a further 1 minute or until wilted. Stir through cooked sweet potato.
Combine eggs and milk in a bowl. Pour into the pan over the top of the veggies. Sprinkle the goat's cheese on top. Cook for 2 minutes or until egg base is set. Transfer to oven and cook for 2-3 minutes until set.