To make the slaw, mix cabbage, red onion and dill pickles, mayonnaise, yoghurt, mustard and pickle juice in a bowl. Season with salt and pepper and set aside.
Divide the mince into 8 loose balls. Do not pack tightly — keeping them loose helps create crispy edges when smashed.
Heat a frying pan or BBQ plate over high heat.
Add olive oil, then place the mince balls into the pan. Immediately smash each ball firmly with a spatula to form thin patties.
Season with salt and pepper.
Cook for 2–3 minutes until the edges crisp. Flip the burgers and top with cheese.
Cook for a further 1–2 minutes until the cheese melts.
Lightly toast the cut sides of the buns on the pan or grill.
Place two burgers onto the toasted buns, spoon over the pickle slaw, and add tomato or lettuce if desired.
Serve with sweet potato fries, or a simple salad.