White Castle Recipe

Slice the onion

Peel the medium yellow onion and slice as thinly as possible into rings. Separate the rings into individual half-moons if desired so they will cook and steam quickly.

Place the sliced onion in a small bowl, add 1 tablespoon white vinegar and 1/2 teaspoon kosher salt, toss to combine, and set aside for at least 10 minutes while you prepare the patties. The vinegar brightens the onions and mimics the slightly pickled flavor of White Castle onions.

Transfer 1 lb of cold ground beef to a large mixing bowl. Add 1 tsp salt, 1/2 tsp black pepper, 1/4 tsp garlic powder, 1/4 tsp onion powder and 2 tablespoons cold water. The water helps the meat spread thin and stay tender.

Using your hands or a spatula, mix just until combined—do not overwork. Divide the meat into two equal portions and, on a piece of parchment or plastic wrap, press each portion into a very thin rectangle about 8 x 6 inches and roughly 1/8 inch thick. The thinner the better for authentic texture. If you prefer uniform round sliders, use a round 3-inch cutter and press to same thickness.

Use a knife or pizza cutter to score each meat sheet into four equal squares or 8 small squares total (so each rectangle yields 4 or more sliders). Transfer the scored meat (still on the parchment) to a baking sheet and refrigerate for 10 minutes to firm up; chilling makes it easier to transfer to the pan without tearing.

Heat a large nonstick or cast-iron skillet over medium-high heat and add 1 teaspoon neutral oil, swirling to coat the surface.

Carefully slide the meat squares from the parchment into the hot skillet (do not overcrowd; do in two batches if necessary). Cook undisturbed 1 to 1.5 minutes until the bottom browns slightly.

Flip each patty using a thin spatula. Immediately scatter the prepared sliced onions evenly over the patties in the skillet (use about half the onions for the first batch). Pour 2 tablespoons (about 1/8 cup) of beef or vegetable broth around the patties (not directly on the cheese area later) and quickly cover the pan with a tight-fitting lid. Reduce heat to medium-low and steam for 1.5 to 2 minutes. The steam will cook the patties thinly and soften the onions—this step is key to the White Castle texture.

Remove the lid, uncover and let any remaining liquid evaporate for 15–30 seconds over medium heat so patties get a little more browning. Place a slice of American cheese on each patty, cover again for 20–30 seconds until the cheese melts.

While the second batch cooks (if you cooked in batches), split the slider buns and brush the cut sides lightly with 1 tablespoon melted butter if using. Toast cut side down in another skillet or under a broiler for 1–2 minutes until lightly golden.

When patties are ready, transfer each cheese-topped patty onto a toasted bun bottom. Top with a few of the cooked onions from the pan and add 1–2 pickle slices if desired. Cap with the bun top and serve immediately.