Curried Carrot Soup

Ingredients 2 tablespoons butter 1 cup chopped onion 1 teaspoon curry powder Coarse salt and ground pepper 3 ½ cups (2 cans) chicken broth 1 or 2 tablespoons lemon juice 2 pounds carrots, peeled and cut into 1-inch chunks (Optional) Garnish with cilantro or a dollop...