Preheat oven to 400ºF.
Place the cauliflower and onion on a baking sheet. Toss with, vegetable oil, cumin and salt & pepper to taste.
Place in the oven and roast until softened and golden brown, turning halfway through cooking, about 20 minutes.
Transfer the cauliflower to a soup pot along with the pomegranate juice and 2 cups of water. Simmer for 10 minutes.
Allow to cool slightly before pureeing in batches in a blender or food processor.
Taste and adjust seasoning. Reheat before dividing between 4 bowls. Sprinkle with sunflower seeds and mint.