Preheat your oven to 200C.
Peel and roughly chop the shallots, core and roughly chop the pears, then add to a food processor with the pancetta cubes and parsley.
Process until finely chopped but not "mushy".
Melt the butter in a medium pan over a low heat, then add the processed mix and cook until softened.
Pour the mix into a bowl, crumble the chestnuts into it, then add the chestnut purée and the breadcrumbs. Mix all with your hands.
Grease the baking dish and put the mixture into it.
Bake uncovered for 30-40 minutes. This can be done under your turkey.
Note: You can use this stuffing inside your turkey or goose instead of making it separately.