To make the massaman sauce, add all of the ingredients to a high-speed blender and blend until smooth.
For the curry, add the oil to a frying pan over a medium-high heat. Fry the tofu for 3-4 minutes on each side until crispy.
Add the massaman sauce, sweet potato and red pepper to the pan, then simmer for 15 minutes until the sweet potato is cooked through. Season to taste.
