not necessarily a treat, but to bulk out some meals such as salad I make 1 point coleslaw
Just grate (with a grater or an attachment for a food processor) a little bit each of white cabbage, carrot and red onion. if using a grater it is usually best to very thinly slice the onions as they can go mushy and to do the same with the cabbage - although texture wise it is up to you how to do it. I then mix it with 2 tbsp of lighter than light mayo and some mustard powder and black pepper. really feels like a treat, and great when everyone else is eating full fat coleslaw and you are tempted (tesco finest chunky coleslaw is my downfall!)