Flake the salmon and remove the bones and skin.
Slice the potatoes in half and scoop out the meat. Save in a bowl. Set the skins to the side.
Add the onion, milk, salt and pepper to the potato meat and mash.
Add the salmon and mix lightly together.
Stuff the potato skins with the potato/salmon mixture.
Cover the top with the bread crumbs. Place a dot of butter on the top.
Bake at 400 degrees for 25 minutes.