Prepare a loaf tin by greasing it with butter then line it with the bacon
Preheat the oven to 160C
Melt the butter in a pan and fry the onions over a medium heat until softened
Add the chopped sage and season well with salt and black pepper, cook for a further two minutes, then remove from the heat
Get the sausage meat into a large bowl, then add the cooked onions & sage, breadcrumbs, the chopped chestnut then the grated apple and combine well
Spoon into a loaf tin and top with the remaining bacon slices
Bake in the oven for about 45 minutes, then remove from oven and drain any excess fat/liquid
Skim around the tin with a knife to loosen the bacon from the tin and place a plate on top, then flip the loaf onto the plate and carefully slide it back into the loaf tin
Return to the oven for 15 more minutes or until all sides are crispy
If freezing, defrost in the fridge overnight before cooking
