I couldn’t help but think of my Foldtuk container when I read this, TBH.  You can put the ingredients in it beforehand, throw it in the fridge or freezer, and then just put it in the oven when you are ready to use it.  It’s the most versatile item in my kitchen, travels well, will collapse when you’re done… I think it would impress your friends to have an instant pasta bake or casserole!