For the burger, place the chopped steak, breadcrumbs, garlic, salt, freshly ground black pepper, Worcestershire sauce and mustard into a mini blender and pulse until coarsely chopped and combined. Using your hands, shape the mixture into a patty.
Heat a little olive oil in a frying pan and fry the burger over a medium heat until golden-brown and cooked through. Place the Stilton on top and leave over a low heat until melted.
Place one slice of crusty white bread onto a serving plate, top with the burger and then place the other slice of bread on top.
Meanwhile, for the spicy potato wedges, place the potato wedges, chilli flakes, salt, freshly ground black pepper, olive oil and butter into an ovenproof pan and place over a medium heat, shaking the pan from time to time, until beginning to turn golden-brown. Place in the oven and roast for 15 minutes, or until golden-brown all over and cooked all the way through.
To serve, pile the potato wedges onto the plate with the burger and garnish with parsley.