Whenever I make a loaf of gluten free bread, I can't seem to eat all of it before it goes stale or moldy. While I could slice and freeze half, I prefer to use it for bread pudding, stuffing, meatloaf, etc. This is an excellent use for bread that is too hard and stale to eat. I would not make it from fresh squishy bread, as I think it would probably dissolve in the egg custard. The original recipe, Debbie Tate's "Make Ahead French Toast" at allrecipes, suggests 8 slices of French bread. I would assume that sourdough, old hard sandwich rolls, etc. would also work beautifully. This morning I used the last quarter loaf of bread made from Bob's Red Mill GF Homemade Wonderful Bread Mix. I would be happy to serve this for company, or Christmas morning. It is *extremely* rich - most people will be too full to finish off two helpings.