Why can't my Sim make Ambrosia?

Thanks Karritz and TreyNutz - I feel so silly, I spent days and days perfecting the quality of the fish and fruit when really, all that was wrong was the serving size! I was trying to make a group serving.

Thanks everyone else for your tips. I'm not ready to feed it to anyone, at least not yet, I was just trying to fulfill a wish that had been sitting with my Sim for a long time.