Preheat a cast iron pan on a medium heat.
Slice and butter one side of each slice generously.
Turn butterside out and spread one slice of the bread with Leek-Chi.
Top with loads of sliced cheese of choice.
Press down with the other slice, butter side up and transfer to the hot pan. Add more butter if required. Turn heat down if necessary.
Cook for at least 7 minutes on one side. Flip and cook the other side for around 4 minutes. You can add a weight in the form of another cast iron pan on top for a better result.
Alternatively use a sandwich press, but I personally love a toastie to be well, toastie!