Ok - I've got THESE: Queen of the Kitchen: Gluten Free Swedish Meatballs in the pan right now. They're simmering in 2 cups of half and half, and after an hour, the recipe states that I'm supposed to add cornstarch to thicken the sauce. I know there are substitutes like potato starch, tapioca, arrowroot etc....what I'm wondering is if it's really necessary to add the starch at all? I know my "gravy" won't be very gravy-like, but is it going to make a big difference?

I'm NOT AT ALL familiar with cooking meat/gravy, so any input is welcome!!!