Place the carrots, onion, and garlic cloves on a large rimmed baking sheet and toss with the oil and sweetener to coat. Spread out the vegetables into a single layer.
Roast for 20 minutes. Stir and spread the vegetables back into a single layer. Roast for 20 to 25 more minutes, or until soft and browned around the edges, but not burned.
Transfer the roasted vegetables to your blender or food processor and add the broth. Blend for 2 to 3 minutes, or until relatively smooth. This may need to be done in two batches.
Pour the carrot mixture into a large saucepan over medium-low heat. Stir in the coconut milk and desired amount of water to thin. Season with the salt and pepper to taste. Cook until heated through.
Ladle into bowls. If desired, swirl with a little coconut cream or coconut milk and sprinkle with minced fresh parsley.
Store leftovers in an airtight container in the refrigerator for up to 2 days.
Notes
Flavor variation: While heating in step 5, stir in 2 to 3 teaspoons of your favorite curry powder.