Julia is a fair to average chef. She sucks sometimes, but can also turn out some good dishes.
Julia burns stuff in the kitchen all the time, but she can make a decent meal sometimes.
Julia is a One-Note Cook. She can cook one dish with no problem, but any attempt to cook anything else will end badly.
Julia thinks she's a good cook, but isn't.
Julia isn't old enough to understand the basics of cooking.
Julia is dyslexic, so she has a hard time reading and comprehending the recipes.
Julia is a stoner and/or Cloud Cuckoolander and comes up with her culinary experiments while high or in one of her "wacky" moods.
Julia was never taught how to cook at any point in her life, and had to make do with what she gleaned from television and watching others, which ping-pongs between "Not bad, for someone who's never done it in her life" to "Very bad, even for someone who's never done it in her life"
Julia is an alien from another planet (or a Funny Foreigner from another country) where the standards of what's tasty and what isn't are very warped.
There is a body count associated with Julia's cooking (Exaggerated #3), but the deaths are due to diseases from severe unbalances in nutrition values. If anything, the taste is actually quite good.
There was one occasion when Julia's food tasted appalling. However, that was because the only available ingredients were so bad, even award-winning chef Monsieur Le Bien could not make anything decent either.
Double Subverted: She ordered take out that time.
Julia's culinary "experiments" have caught the attention of the Center for Disease Control and after her latest attempt at dinner, the CDC come in and quarantine her kitchen.
Julia's cooking ability depends on what ingredients she has in her house. When she has enough money for groceries, she makes great food; when money's tight, it's time to break out the Tums and the airline barfbags.
Julia sucks at cooking actual dishes (appetizers and main courses), but is a whiz at baking and pastries.
Julia is too lazy to cook and has never tried.
Julia's cooking isn't terrible, but it's not Cordon Bleu quality either.
Enforced: "What better way to paint Julia as a ditzy Cloudcuckoolander than to have her completely unable to cook? Brilliant!"