i used to do a weekly shop every week, where i would buy and choose everything that the children ate (breakfast / lunch / dinner / snacks / puddings)
I always cook from scatch (because i prefer to) but MB wouldnt have mind if i didnt cook every single meal from scratch... so it was much easier for me to just go shopping and get all the ingrediants i needed, for the recipies i had planned.
MB was busy at work, we never had time to discuss it, we could have made time, but didnt see the point.
(Also as a rule each week I would serve at least one potatoe, rice and a pasta based meal, AND, a meal with mince / chicken / fish / "proper meat" / vegetarian, so the children had a nicely balanced and varied diet.
Lunches were normally, soup, filled jacket potate, sandwich, other form of bread type product + "whatever we felt like"
Basically i did a shop every Monday, and if MB wanted something (anything at all sold in waitrose)she'd text me and id willingly buy it as well, while i was there, but it meant for 5 days a week they didnt need to think about feeding their children at all.
(I wouldnt plan their weekend food, but there were always portions of frozen home made meals if necessary, but MB / DB were both fab cooks, and they would almost always give the children whatever they were having at the weekend.