Roast the Squash: Preheat your oven to 400°F (200°C). Toss the cubed butternut squash with olive oil, salt, pepper, and a sprinkle of cumin. Arrange the squash in a single layer on a baking sheet. Roast for 25–30 minutes, flipping halfway through, until tender and caramelized.
Sauté the Aromatics: In a large pot, heat a bit of olive oil over medium heat. Add the chopped onion and cook until softened, about 5 minutes. Add the minced garlic and cook for an additional 1 minute, making sure not to let it brown too much, as that can turn it bitter.
Combine the Ingredients: Once the squash is roasted, add it to the pot with the onion and garlic. Pour in the vegetable broth and fresh thyme. Bring everything to a simmer for about 10 minutes to let the flavors meld together.
Blend the Soup: Remove the thyme sprigs and carefully blend the soup using an immersion blender, or transfer to a countertop blender. Blend until the soup is completely smooth and creamy. If it’s too thick, add a bit more broth or water to reach your desired consistency.
Finish the Soup: Stir in the coconut milk and adjust the seasoning with salt and pepper to taste. Let it simmer for an additional 5 minutes to heat through. Serve hot with optional toppings like roasted pumpkin seeds, a drizzle of coconut milk, or a sprinkle of fresh herbs.