I enter my recipes for marinades, sauces, and similar things separately from the recipes I use them in. For instance, I have a recipe for a coleslaw dressing that I make. I also have a recipe for the coleslaw veggie mix that I especially like. When I make my coleslaw, all I have to do is go to my Recipes list and select the recipe for Coleslaw Dressing and enter that as one of the ingredients. Then I can just adjust the amount of dressing to match how much I used in my Coleslaw.

So, if you enter the teriyaki sauce as a separate recipe, you can just select it from your Recipe list and adjust the amount to however much you end up eating with your kebabs.