I remember being befuddled by the same thing at this stage. The teens were in and out so much and didn’t communicate well.
At the same time they were growing fast and were hungry and I didn’t want them eating junk.
It was never perfect but I got through it by sticking to my weekly meal plan.
Sun - Sunday lunch or dinner with all the trimmings Everyone present.
Mon - easy leftovers, bubble and squeak or cottage or shepherds pie, or cold cuts with salad or veg
Tues and Thurs - veggie pasta or rice dishes or chick pea or lentil casserole with plenty of integral veg; pre-prepared and left in bowls in fridge for people to help themselves and microwave.
Wed- tray bake chicken or sausages with veg if everyone present, if not, slow cooker mince veg for fajitas, chilli etc.
Fri- fish in form of pie or microwaveable packets, or breaded in air fryer, with mash or air fryer chips, frozen peas.
Sat- fakeaway from Hairy Bikers book cooked by teens themselves but day got moved every so often.
The main thing I changed was that I moved obligatory Sun lunch to Monday night at some point but the idea is, to have at least one, ideally two, meals minimum a week where everyone present. And it makes sense if that is your Sunday lunch equivalent, even if it is on another day. And then say a good meal on Wednesday or Thurs and then you know they are fed well twice a week minimum.
The other thing was that we didn’t give money for takeaways very readily until the bowls of food in fridge were eaten.
And to help with that, I baked once a week on Thursday and made healthy(ish) cakes and snacks. Made soups in winter.
There were lots of times it all went to pot of course but that was roughly the plan.
Holidays are hard because the food just disappears. And the ££££ are disappears too. I have never known food be so expensive as it is now.
I have seasonal bowls of fresh fruit, restocked. And things like cheese and ham, salad and wraps. Eggs. Noodles. Baking spuds.
I only buy water, tea, coffee and milk. No fizzy drinks or cordials. Stopped buying crisps or chocolate bc of budget. If they want that stuff it comes out of their own allowance.
I have two big metal tins; one with the baking in, and one with biscuits in. The dc know that if they eat everything in both tins during the first two days, then it’s not replenished until next week when I do my big Thursday shop and my baking.
Ultimately op, you can drive yourself spare trying to fit in with everyone else. If you are mainly doing cooking and shopping I think you need a system that works for you. I think it benefits everyone if you take a fairly militant approach because they then get with the plan
But only aim for consistency 80% of the time or you will go insane with it all! Especially when it’s a hot summer and you don’t feel like cooking.
Barbecues and big composed salads are fine. My teens eat them if we serve them with tuna or sometimes I roast a gammon ham for cold and then put chips in air fryer.