Do a once a week at a good local shop for meat and a mixed assortment of veg.
Have a load of stuff, fishfingers, m&s chicken breast fillets in breadcrumbs etc, couple of m&s readymeals and a pizza or two in the freezer. Plus whenever I make things I make a vat-full and freeze several portions so there is always stuff like homemade chilli, ragu, cottage pie, chicken casserole, fish pie available.
I can rely on DH only being home for dinner five nights out of seven and I never know until the last minute which nights he'll be out so meal planning would never ever work.