A really simple and tasty dish that is so versatile and open to so many interpretations. Great for a starter, side or snack dish, or why not stick it into a bun for a veggie burger! I've used toasted pine nuts, but hazelnuts would be good too. Stilton and Cambezola cheese work really well too and Cheddar is an obvious choice if you don't do blue cheese. I bet fresh mozzarella would be great too. Chopped bacon can also be added to the leek for another variation.