White Castle: What’s Vegetarian Editorial Review

White Castle finally has a real vegetarian main, the Southwest Veggie Slider, and that’s a genuine change from the Impossible Slider era. The chain discontinued the Impossible Slider at the end of 2025 and replaced it with a Dr. Praeger’s veggie patty that rolled out to every one of its 336 restaurants in June 2026.

What to order at White Castle

The Southwest Veggie Slider is built from a Dr. Praeger’s patty of sweet potatoes, black beans, corn, red bell peppers, onions, and carrots, held together with a crispy brown rice crust. Order it without cheese and mayo and it’s vegan. French fries, Hash Brown Nibblers, and Mott’s applesauce round out a full meal, and the caramelized onions and slider bun are both vegan as served.

What to watch out for

The default Southwest Veggie Slider comes topped with jalapeno cheese, which makes it vegetarian, not vegan, so speak up if you want it dairy-free. French fries, Hash Brown Nibblers, and onion rings all share a fryer, which matters if you’re strict about cross-contact. Onion rings and onion chips also contain milk in New York and New Jersey specifically, a real regional catch. White Castle’s footprint is smaller than its fame suggests, concentrated in the Midwest and Northeast, so check that a location is actually near you before you plan a trip.