Place mince, breadcrumbs, cheese and onion in a medium bowl. Season with salt and pepper. Mix well to combine. Using heaped tablespoons of mixture at a time, shape into 12 patties.
Heat oil in a large non-stick frying pan over medium-high heat. Cook patties for 3-4 minutes each side or until browned and cooked through.
Meanwhile, place coleslaw, parsley, dressing and 1 tablespoon water in a medium bowl. Toss gently to combine. To assemble, top each panini base with lettuce, coleslaw, then a pattie and pickle slices. Sandwich with panini tops and secure with toothpicks.