This is such a happily simple soup. The key is to roast the beets instead of buying the precooked ones at the store. As the beets bake with olive oil and salt in the oven, they soften and their edges become sweet and caramelized. I purée the roast beets with softened leeks, vegetable broth, woodsy thyme, and a squirt of lemon juice that balances the sweetness of the beets and leeks. The resulting soup is thick, vegetal, and autumnal. A quick dollop of crème fraîche on top lightens the color and flavor and adds richness.
- 5 medium beets (about 2 pounds), peeled and cut into 1 1/2-inch dice
- 3 teaspoons olive oil, divided
- Kosher salt and freshly ground black pepper
- 1 small leek, white and light green parts sliced (about 1 cup)
- 2 teaspoons picked fresh thyme leaves, plus more for garnish
- 4 cups low sodium home-made or store-bought vegetable or chicken broth
- 1 tablespoon juice from 1 lemon
- 1/4 cup crème fraîche
Adjust oven rack to center position and preheat the oven to 400°F. In a large bowl, toss beets with 1 tablespoon olive oil and season with salt and pepper. Transfer to a parchment-lined rimmed baking sheet. Roast until tender to the point of a knife, 30 to 45 minutes. Set aside 1/2 cup beets and cut into 1/2-inch dice for garnish.
Add the remaining 2 tablespoons olive oil to a large saucepan. Add the sliced leeks and thyme, and season with salt and pepper. Set heat to medium-low and cook, stirring frequently, until leeks are tender but not browned, about 5 minutes. Add the roasted beets and broth and bring to a boil.
Purée soup using an immersion blender or a standing blender, then stir in lemon juice. Season to taste with more salt and pepper as necessary. Serve immediately with a dollop of crème fraîche, garnished with cubed beet and extra thyme leaves.