Preheat and lightly oil the barbecue for medium-high heat.
Mix the beef mince, pork sausage mince, parmesan cheese, eggs, sweet onion, garlic, onion soup mix, Worcestershire sauce, salt and pepper together in a bowl until evenly incorporated. Shape into 10 patties.
Cook on the preheated barbecue until the burgers are cooked through and no longer pink in the centre, about 10 minutes per side. An instant-read thermometer inserted into the centre should read 70 degrees C.