123888, this is how I do it:
I have tons of recipes loaded to my custom foods. After cooking a dish, I enter all the recipe total ingredients on a blank page of my food log. Then (and here's the tricky part for soup) I determine how many servings it made. Well, we all know a serving "size" is a relative thing. I personally call a serving of soup for an adult 1.5 cups, but most people say 1 cup. Once I have determined how many servings I consider the recipe makes, I divide the figures Fitday gave me by the number of servings to get the nutritional info for ONE serving. And don't forget to divide the fiber by # servings as well! I jot my serving numbers on a piece of paper. Then I load up a CUSTOM FOOD, being sure to include serving size (1.5 c) as part of the food/recipe name (since Fitday shows 1 serving only).
For example: Soup, Tuscan Bean, 1.5 c
And then I enter all the numbers and click the SAVE button.
That's all there is to it!