In a large bowl combine the onion, garlic, sausage mince, bacon, bread crumbs, tomato paste, vegemite, and 2 eggs.
Prepare the barbecue for indirect cooking over medium heat (180° to 230°C). If using a Weber Q barbecue, set up your barbecue with a convection tray and a trivet.
Cut a sheet of pastry in half. Shape the mixture into sausages and place in the middle of each half of pastry. Using a pastry brush, brush the edges with egg. Roll up the pastry to enclose the mixture. Cut each roll into six equal portions.
Place the sausage rolls onto lined baking trays. Using a pastry brush, brush the lightly beaten egg on the sausage rolls and finish with a sprinkle of sesame seeds. Repeat with remaining pastry and mince mixture.
Cook the sausage rolls over indirect medium heat, with the lid closed, for 30 to 40 minutes, or until the pastry is deep golden.
Cook the sausage rolls over medium heat, with the lid closed, for 30 to 40 minutes, or until the pastry is deep golden.