In a saucepan, on the side burner (or stove top) over a low heat, melt the butter.
Once the butter has melted add the onion. Fry for a few minutes or until golden and just beginning to soften.
Once the onion is cooked, remove it from the heat, and set aside to cool.
Prepare the barbecue for indirect cooking over medium heat (190°C to 230°C). If using a Weber Q barbecue, set up your barbecue with a convection tray and a trivet.
Once the onion is cooled, mix with the remaining ingredients. Using heaped tablespoons worth of mixture, roll into balls.
Put the stuffing balls into a drip pan that has been lightly greased with butter.
Roast the stuffing balls over indirect medium heat for 10 to 15 minutes, or until cooked through.