Cornstarch will be fine. Probably use about half as much, which I'm sure you know more about it than I do.I couldn't live without bacon grease. That gravy sounds good rkunsaw but I'd have to use cornstarch to thicken it because of the gluten in the flour and use gluten free biscuits. Grits I like to eat like a cereal with sugar and milk. It tastes just like farina .