One of the ideas was to do a personification of food with name such as 'hot dog', 'french fries', 'jawbreaker', chocolate mousse' etc. One of the inspirations is the movie 'Willy Wonka and the Chocolate Factory': http://mentalfloss.com/article/68399/11-wonderful-words-willy-wonka-and-chocolate-factory
Cakes in the style of this film: https://uk.pinterest.com/scrib9877/cakes-willy-wonka-the-chocolate-factory/
From here I thought I can go with sweet stuff mostly so I looked up desserts across the globe from here: https://en.wikipedia.org/wiki/List_of_desserts#Dessert_sauces and idioms from here http://www.dailywritingtips.com/25-idioms-about-bread-and-dessert/ and here https://www.englishclub.com/ref/Idioms/.
I found nice galleries on Pinterest about idioms and language in general:
Another idea I got was to create a world inspired by pizza Four Seasons. Winter would be always sad, because everyone runs away from her in tears, as she is made out of inion and cheese. Summer would be spicy, made from peppers and pepperoni. Autumn would be made out of potatoes and mushrooms and spring would be all veggie and healthy.