Aaaargh - I was going to post how easy pie-making is in general, but you beat me to it.
That’s it above. Not rocket surgery. Apply to beef, lamb, chicken, veggies - whatever (I’ve put pasta pieces in mine to bulk it out sometimes). You can use pre-cooked left-overs, or make from scratch.If you want pastry on the bottom - fine. If you don’t - fine. If you want pastry on top - fine. If you want to use potato slices as a base - go for it. If you want mashed potato on top - fine. If you just want to lay slices of bread on top (a good way to get the topping to soak up all your lovely gravy) - fine (cook longer at lower temperature).
Chuck in whatever you want - mix up the flavours (I always love some peas in my pies), experiment with sauces and gravies. The ultimate test of a pie is ‘How good do the leftovers taste the next day’?
It also means you’ve made a good start on cleaning out the fridge that you’ve been meaning to do for a few weeks.
As regard dishes - I generally only use two. A fry-pan/saute pan for the initial cook of meat and veg - just add and remove as required. Chuck it in a pot. Add topping (whatever). put in oven for anywhere from 15-40 mins (depending).