Preheat your Blackstone griddle to medium-high heat.
Divide the mince into 8 equal 78g balls, being careful not to overwork the meat.
In a bowl, mix all sauce ingredients until smooth, then place in the fridge to rest.
Lightly oil the griddle.
Place the beef balls onto the griddle and let them sit for 10 seconds. Season with salt, then smash into thin patties. Cook for 60–90 seconds, until the edges are crispy.
Flip the patties, season lightly again with salt, and add cheese to 4 of them. Cook for another 45–60 seconds, until the cheese is melted.
Lightly toast all bun pieces on the griddle until golden.
To build each burger, start with the bottom bun, then add a spoon of sauce, shredded lettuce, and one cheese-topped patty.
Place the middle bun layer on top, then add another spoon of sauce, diced onion, pickle slices, and the second cheese-topped patty.
Finish with more shredded lettuce and the top bun. Gently press the burger together, serve immediately, and enjoy.
