Giant Sausage Roll - Cooking like a Boss

preheat oven 200*c							bake for 40 minutes
1 large onion	chopped	mash together in a bowl	lay meat along centre	seal pastry into giant sausage roll shape	flip so join is on bottom	slice air vents in top
375g ³⁄₈kg 0.827lb 13.2oz sausage meat
170g 0.17kg 0.375lb 6oz cheddar cheese	grated
2 tablespoons 0.03 l 30 ml 6 tsp 0.127 cup 0.053 pint tomato puree
4 sundried tomatoes	finely chopped
2 tablespoons 0.03 l 30 ml 6 tsp 0.127 cup 0.053 pint fresh breadcrumbs
1 egg	beaten
320g 0.32kg 0.705lb 11.3oz puff pastry sheet
milk