Apple sauce under melted cheese. Sounds wrong, is right.
About 10 minutes from starting to sitting down, and it is straightforward. That is start-to-finish, so it works on a weeknight when you have not planned anything.
Use any loaf that is a day old. Fresh bread turns to paste in most of these.
Not really. This one relies on being crisp, and crisp does not survive the fridge. Prepare the components ahead if you like, but cook it just before eating.
Yes, it is vegetarian. It is not vegan as written because it contains dairy; swap the dairy for a plant alternative and the rest of the method is unchanged.
Bread, potatoes or a simple salad. It serves two as written. Double everything to feed four, but use a wider pan so the food still browns rather than steams.