Sweet Potato Soup with Pumpernickel Croutons

• 4 tablespoons olive oil
• 1 onion, chopped
• 2 garlic cloves, finely chopped

Heat 2 tablespoons of the olive oil in a heavy pan and add the onion. Cook, stirring, over a medium heat for 5 minutes until soft. Add the garlic and curry powder and cook, stirring, for a few minutes more. Add the sweet potato and apple and stir well to combine with the other ingredients. Cook, sti