There’s only one proper way to introduce sauce to a meat pie. This is it.
Take one meat pie, heat it up as per instructions on the box. This is no place for fancy homemade pies. Take a sharp knife and carefully slice off the lid of the pie. Yes, the lid.
It should look like the below. If it doesn’t, you’ve done it all wrong. Take your sauce of choice. Tomato is the best and most obvious one.
Squeeze the required amount of sauce into the meaty juicy casserole filling.
Stir it in with a fork. Or a spoon. Or your finger. I don’t care which.
Replace the lid. It’ll basically look like nothing untoward has ever happened to this pie, even though you just basically undressed it and had a swill around.
Eat well. Then eat nothing else all day due to guilt, albeit happily replete guilt.