Start by gently frying the chopped onions in a little butter or oil until they become soft and translucent — this takes about 8–10 minutes. Add the chopped sage and thyme, stirring for a minute so the flavours release. This step ensures the herbs don’t taste raw and the onions add sweetness.
In your mixing bowl, put in the sausage meat, breadcrumbs, beaten eggs, chopped parsley, melted butter and seasoning. Then add the cooled onion-herb mixture and stir everything until it’s evenly mixed. Making sure the breadcrumbs soak up the juices helps the stuffing hold together.
Spoon the mixture into your greased baking dish and smooth the top. Bake in a pre-heated oven (about 180 °C/350 °F) for ~30–35 minutes until the top is golden and the sausage meat is cooked through (internal temperature safe). Remove and let it rest for a few minutes before serving so it holds its shape nicely.