nraas

I have a problem in that all of my houses inevitably end up littered with rotting food because all my sims, when hungry, insisting on "serving" a meal instead of "having" one, thus producing an excess amount of multiple portioned meals. Is there a way to change this behavior and make them more likely to just cook a single serving for themselves?

If you mean when they cook to make just 1 serving yes and no. You can change the amount of servings made although the XML you would have to edit escapes me and I don't currently have time to look for it. But in doing so you'll most likely end up with an even bigger problem as it would affect the whole town you'll end up with a bunch of sims trying to cook all at the same time and lagging the game out due to routing errors caused by repeatedly queueing up the cook interaction.
You can try to disable autonomy for cooking but you could then end up with a town full of sims starving to death.

You can when your sims get hungry take control and direct them to the fridge to Eat Leftovers.
You can also direct them to Have a Quick Meal and if you have a microwave on the lot it gives more options. But quick meals are unsatisfying and they'll get hungry again faster. Sims rarely pick a quick meal for that reason and I don't see anyway offhand to change that.

I've got the same problem. I've got two decent mid-level cooks in the household, but sims insist of serving burnt mac and cheese, often while one of the two better cooks is preparing dinner. I wouldn't mind if they went for a quick meal. To make matters worse, they then get wishes to learn the recipe for any meal they eat. These non-cooks have too many other things to focus on that cooking is totally irrelevant. My present solution, so far is:

Sim > NRass > Master Controller > Advanced > Skill Level > Cooking > 0

At least that removes the skill so they don't get cooking related wishes.

to really remove it you need to set the level to -1

Even the thread is a little old...
I would give one sim of your household a high cooking skill.
At twoftmama there is a mod for make them use ready cooked meal, and leftovers from the fridge rather than always cooking themselves.
So if one cooks a lot good food fill your fridge
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Or this mod
http://modthesims.info/d/386354/eat-amp ... overs.html

While out on an adventure to China, I had my Sims buy and eat some Dim Sum. That stupid idiot who burnt the mac and cheese, had three pending wishes. Learn how to make Dim Sum, Increase Cooking Skill, Take a Cooking Class. Everybody else got the wish to collect 5,000 worth of relics. The idiot didn't because his wish slots were full. Just ranting here. Hope you get a laugh out of my exasperation.

But you can delete wishes you don't like, I mean the game throws out random stuff without sense. Also opportunities can be cancelled and you can choose via MC new ones.