She ate pizza in Rainbow Rocks, and I've read quite a few stories involving her either being a vegetarian or omnivorous. I leaned on her being a vegetarian in Other Voices since at the time it was still the pony version.

The reason I ask is I am now just about to write a chapter in the Jongojiverse "Equestria Girls" where Sunset has dinner with Twilight at her residence and I don't want her to eat kale and bison stew as one of my OC's do.

This can imply to both the pony and human counterparts.

Italian Style Wedding Soup

4980855 My take on it is that Sunset's come to accept eating some meats, specifically chicken and pork. She avoids beef, venison and mutton because cattle, deer and sheep are all sapient in Equestria, and she can justify dairy products and eggs because she no doubt consumed them back home.

As for her favorite food? I've got her as a fan of spaghetti.