Oven-Roasted Beet Soup with Watercress

Ingredients

• 2 1/2 pounds beets, greens removed and washed
• 2 tablespoons extra-virgin olive oil
• Salt and freshly ground black pepper
• 1 large red onion, minced
• 5 cups chicken stock
• 1 bunch watercress, stems removed, chopped
• 1/2 cup crème fraîche
• 1 teaspoon lemon juice