"was lamenting recently how boring eating had become. She was irritated that recipes all seem to say "serves 4" or "serves 6" or whatever, and she doesn't want to eat the same thing all week, but she does want to follow the recipe to make sure things taste right and to avoid dealing with weird subdivided measurements."

Sadly - this is the attitude of a depressed 'consumer'.

1) Seriously, think about medical help and antidepressants.

2) Start experimenting - you can't poison yourself by mixing things at random - but you WILL get some weird tastes...

3) Some single serve things like "Pot Noodles" exist, but are more expensive than bulk ingredients.