So you know they won't eat sandwiches or toast, so why offer then it.
I wood run a cafe however I won't force my children to eat means they don't like.
Ds1 wont eat anything with sauces, cabbage, mince, processed food (chicken nuggets, fish fingers etc... he also does not like kidney beans or cannoli beans, however does like baked beans and loves most lentils.
skin veg i.e., tomato , peppers, mushroom onion etc.. won't eat anything with Italian herbs either.
Ds2 can only eat root veg, farm meat, fish, etc...
I have to make meals which they like and will eat.
I'd be very unhappy that they made me abandon our food shop however I would not punish them through food, and you cannot force them to eat foods they don't like, as ultimately they would just be ill.
Ds1 would end up having a bowl of cereal or something, and ds2 would end up having rice and veg.
Punish them, however just don't punish them with food.