selecting a serving size of a meal that I created

I input all of the ingredients for a home made pizza to create a special recipe 'home made veggie pizza' but I only eat 1/4 for the meal.. How do I create a serving size for a meal that I created? Or should I have created a 'food' item rather than a meal?

I don't know if there's an easier way but I input homemade dishes as recipes in my cookbook - you don't have to publish them, just save - then you can state how many it serves and FS will calculate calories for one serving. You can then go back to your cookbook and select a portion the next time you make the same meal.