Preheat oven to 180°C.
Line a roasting tray with baking paper and add the carrots, onions, garlic, fennel seeds and cumin seeds. Drizzle with olive oil, and gently toss to coat.
Slice one of the oranges into rounds and place on top of the carrots. Roast for 25-30 minutes, until the carrots are soft and lightly browned.
Zest and juice the remaining orange. Discard the cooked orange slices and squeeze out the cooked garlic, discarding the skins.
Add orange zest and juice to a blender along with the garlic, the carrots and all of their juices. Season with salt and freshly ground black pepper.
Add half of the vegetable stock and blend, adding more stock as necessary, until you have a smooth soup. Taste, and adjust seasoning if needed.
Serve hot with a drizzle of olive oil and some freshly ground black pepper.
