Put the beef chunks on a baking sheet in a single layer, leaving 1/2 inch of space around each chunk. Freeze the meat until very firm and starting to harden around the edges but still pliable, 15 to 25 minutes.
Place half of the meat in a food processor and pulse, stopping and redistributing the meat around the bowl as necessary to ensure even grinding, until coarsely ground, 10 to 15 one-second pulses. Transfer the meat back to the baking sheet, overturning the bowl and without directly touching the meat. Repeat the grinding process with the remaining meat. Spread the ground meat over the baking sheet and inspect carefully, discarding any long strands of gristle or large chunks of hard meat or fat.
Heat a cast-iron skillet or large heavy griddle pan over high heat. Divide the meat into 6 portions, then form each into a large, thin patty with your hands; focus on loosely packed meat and a larger circumference than thickness. Season with salt and pepper.
In 2 batches, cook the patties. Press them down once with a spatula as soon as you put them in the skillet. Do not smoosh them again. Cook until crusty brown, 4 to 5 minutes. Flip once and drape 2 pieces of cheese on top of each so it melts down the side while the other side cooks. Cook to the desired temperature.
Set a nonstick pan over medium heat. Butter the pretzel buns and toast until golden brown, about 2 minutes.
Arrange the burgers on the pretzel buns, top with pickled jalapenos and serve with a side of DijOli.
Mix the mayonnaise, Dijon, stone-ground mustard, honey and garlic together in a small bowl. Season to taste.