Heat the oil in a large saucepan. add the garlic and ginger and cook for 2 minutes or so.
Peel and chop the onions, and trim, peel, and chop the carrots. Add to the saucepan with the garlic and ginger, and continue to cook for another 3 to 4 minutes, until the onions are reaching a golden color.
Add the vegetable stock, thyme and blood orange zest. Bring to a boil over a medium-high heat. Once it's boiling, lower the heat, cover and simmer until the carrots are tender, or about another 20 minutes.
Remove from the heat, discard the thyme sprigs, and process the soup using an immersion blender, or other food processor, until it's the desired consistency.
Add the blood orange juice last, and season with salt and pepper to taste.
Top with chopped coriander and serve.