Like wisewoman I always have portions of homemade soup and ragu in the freezer for a quick meal.
But sometimes a ready meal is what is needed. Maybe you need a couple of options, something, quick, hot and filling for your DH when you are out, tinned soup or stew or a frozen curry for lunch. Also a selection of more top of the range meals for when you are too busy to cook.
I think that this is when COOK will be of use, much more like the M&S ready meals, so you feel it is a bit of a treat for the two of you.
I also keep frozen seafood mix to stir into basic risotto or Asian style noodle soup, frozen mash to make fish or shepherds pie from leftovers, and lots of pulses to add depth and interest to left over portions of basics.