I disagree with lots of the replies to this. I totally get your issue and I don't think you're unreasonable to expect to be listened to in your own home and for your children to have some time consideration of costs and how their current behaviour impacts this.
I'd tell them that protein snacks must be cooked weekly in advance in batches to last the full week. They ration them and when they're gone, they're gone.
Pasta - as the weather is getting warmer, they don't need hot pasta. Again, the rule is they cook a huge load of pasta (twice a week) and keep it in the fridge, when they want it, they make pasta salad.
Cooked breakfast can all be done in the air fryer and microwave.
I'd also have to have a serious chat with all of them regarding respect and behaviour. Buying foil trays and paper plates so you stop 'moaning' sounds extremely disrespectful. I'd make it clear that if they're not going to be considerate and instead use wasteful workarounds rather than learn to clean up after themselves, then once they reach adult age, they can leave and then there's no moaning and they can live as they choose. Or they can get a job and pay their way properly, which includes a cleaner every day to clean up after them.
I'd switch the electric off at the mains after dinner. Mine's in a lockable cupboard so quite an easy fix. And if that means no TV, no gaming etc, that'll also impact them hopefully.
And just as a final point, money being right does not mean people can't /shouldn't buy organic oats or avocados or generally good food. People make choices. Money can be very tight AND you can buy nice food. The two can coexist! It's rude and judgemental and based on outdated biased skewed views
Everyone, regardless of economic status (in the UK,eg) should be able to choose good quality food without being stigmatised and made to feel guilty ir told 'money can't be that tight". Why shouldn't less well off people be able to choose to eat avocado or organic products? It's their choice. Trying to shame or question the veracity when someone says money is tight is unkind and shows complete lack of empathy.