Five-Spice Beet Soup

Ingredients

• 4 2-to 2 1/2-inch-diameter beets, scrubbed, trimmed, unpeeled, each cut into 6 wedges (about 3 1/2 cups)
• 3 cups vegetable broth, divided
• 1 tablespoon olive oil
• 1 medium-size red onion, thinly sliced (2 cups)
• 1 celery stalk with leaves, stalk chopped, leaves sliced
• 2 teaspoons grated peeled fresh ginger
• 1/4 teaspoon (or more) Chinese five-spice powder*
• Sour cream or plain yogurt