Onion-steamed sliders (White Castle style)

Beat the ground beef to a paste-like consistency for a tight texture.

Aim for one-ounce patties (the frozen originals weigh about 0.7 ounces and burgers lose about 25% in cooking). Press about eight ounces of beef into a rough rectangle between two sheets of parchment paper.

Roll it out with a dowel rolling pin fitted with four millimeter guides into an even rectangle.

Score into six square patties slightly larger than the bun, using the bun bottom as a template, to allow for shrinkage.

Punch five holes in each patty with a metal straw, pressing and twisting.

Freeze a couple of hours until solid; repeat for 30 patties.

Chop the onions; cut 30 slices of American cheese.

Peel off the parchment and snap the frozen sheet into individual patties; do not refreeze scraps that have thawed to room temperature.

Oil a hot griddle and lay down a big bed of onions; squirt with water so they do not brown too fast and make steam. Sweat two to three minutes until just translucent.

Lay the frozen patties on the onions, close together so steam escapes only through the holes; salt lightly with kosher salt.

Set the bottom buns directly on the patties with the top buns over them to warm the buns and trap steam.

When the onions have colour and the burgers are grey, invert in batches of ten onto a wire rack in a rimmed baking sheet.

Top each with a slice of American cheese and a dill pickle chip, then the hot top bun to melt the cheese.

Repeat with the remaining 20 patties, holding finished burgers in a low oven.

Variation: for a smaller batch, prepare the beef and onions the same way and cook on a cast iron pan.