Carrot Ginger Soup

Ingredients

• 2 tablespoons butter
• 1 tablespoon olive oil
• 1 cup diced onions
• 1/2 cup diced celery
• 1/4 cup minced ginger
• 1 tablespoon minced garlic
• 1/2 pound carrots, peeled and roughly chopped
• 4 to 6 cups chicken stock
• 1 teaspoon salt
• 1/2 teaspoon freshly ground white pepper
• 1 bay leaf
• 1/2 cup heavy cream
• 1/4 cup sour cream
• Chopped chives , for garnish