Preheat oven at 180C.
In a medium saucepan add in grapeseed oil on med-high heat place in the onion, garlic, diced bacon and cook for 4-5 minutes or until the onions are translucent.
Remove from the pan and place into a large mixing bowl with the pork mince, add in the breadcrumbs, egg and mix until all combined.
Season to taste with salt and pepper.
Divide the mixture into 4 even sized portions.
Cut each sheet of pastry in half widthwise.
Working with one portion of meat mixture at a time, place the mince down the middle of the pastry, brush the edges of the pastry lightly with the egg yolk then carefully roll the pastry around the meat to form a log, gently pressing on the join to seal, trim any excess pastry.
Repeat with the remaining three.
Place onto a lined baking tray, brush the sausage rolls with egg yolk, sprinkle with sesame seeds and place in the fridge for 15 min to rest.
Cut each of the sausage rolls in half and place onto a lined baking tray.
Place in the oven to bake for 20-25 minutes or until the puff pastry is golden brown.