Peel the beets and cut them into quarters. On a baking sheet, toss the beet quarters with 1 tablespoon of the olive oil and the salt and pepper to taste. Push the beets to the side of the pan to make room for the garlic and pumpkin.
Peel and discard the loose outer layer from garlic bulb. Slice the top of the bulb off to expose the garlic cloves. Rub the garlic bulb all over with ½ tablespoon of the olive oil. Wrap the bulb in parchment paper and place it seam-side down on the pan with the beets.
Slice the pumpkin in half from stem to base. Scoop out all the seeds and pulp and discard (or save to roast the pumpkin seeds).
Rub each pumpkin half on all sides with 1 tablespoon of the olive oil. Place on the baking sheet with the beets.
Transfer the baking sheet to the oven. Roast the vegetables for 45-55 minutes, or until tender.
Transfer the beets to a food processor or high-speed blender. Allow the pumpkin and garlic to cool until able to handle.
Scoop the flesh from the pumpkin halves and squeeze the garlic into food processor with the beets. Add the vegetable broth and process until completely smooth.
Transfer to a medium pot. Add in the coconut milk, white pepper, and more salt and pepper to taste. Stir to combine. Simmer over medium heat for 2-3 minutes, or until warmed through.
Divide the soup among four bowls. Garnish with the thyme sprigs, drizzle with the remaining olive oil, and serve.
Tip: If fresh pumpkin isn’t available, use 1¼ cup unsweetened pumpkin puree.