Place ground beef in a food processor, blitz a few times to break it down a bit.

Dump ground beef onto a baking sheet lined with parchment paper. Cover with another piece of parchment paper, and roll it thinly and evenly - about ⅜" thick.

Use a square cookie cutter to cut as many patties out as you can. My cutter is 2 ¾", a 3" cutter may have been a little better - the burgers shrink as they cook.

Press the trimmed pieces together, roll out between sheets of parchment paper, and continue til you have 12 patties.

Using the end of a chopstick or similar tool, create 5 holes in each patty - one in the center, one towards each corner. I basically stuck a chopstick in, and made a small circular motion to open and round it out.

Once all patties are formed and full of holes, freeze until firm - at least one hour.

Once frozen, you can stack them - I like to separate them with pieces of parchment, to prevent sticking - place them in an airtight freezer bag, and freeze until you’re ready to use them.

Run the chopped onions through a food processor to finely chop them. You want small pieces, but not a puree.

Place half the chopped onions on a large skillet or in a large nonstick baking pan, along with the dehydrated onions and water. Stir well to combine.

Cook the onions over medium high heat for 5 minutes or so, then add the remaining chopped onions. Lower the heat and cook for another 2 minutes or so.

Spread the onions out in an even layer, covering the bottom of the pan. Arrange the burger patties in a single layer over the onions.

Note: If you can’t / don’t want to do all 12 at once, use half the onions / water and do it in 2 batches of 6.

Cover pan with a lid, let the burgers steam for a few minutes, until the tops appear cooked. If at any point the water dries up, add a little more to keep the steam going..

Top each burger with half a bun. We used the tops, based on what it looked like one restaurant was doing in a video, but it seems like bottoms may have been the standard.

If you have room in the pan, balance the remaining buns over top of the first buns you placed, or set balancing over the onions using the edges of the pan and original bun halves as bases. Don’t place the buns directly in the onions, or they’ll end up soggy.

Once the burgers are fully cooked and the buns are heated through, place them on a plate in one of two ways:

If you put the top buns over the burgers, arrange the bottom buns on a plate. Slide a flat spatula under a burger, and pick it up - onions, bun top, and all - and place it on one of the lower buns. Repeat with the remaining sliders.

Or

If you put the bottom buns on the burgers, slide your spatula under a burger patty and pick it up - onions, bun bottom, and all - and carefully flip the whole thing over on a plate. Repeat with remaining burgers and buns.

Remove top buns (if you cooked them on the burgers), and top your patties with cheese, pickles, ketchup, and/or mustard, as desired. Top each with a bun top.

Serve immediately, with crinkle cut fries!