Cook in boiling, salted water until tender, app. 15 minutes
Drain potatoes, add butter, horseradish and 2 tbs milk to potatoes, mash, adding a bit more milk if needed
Put fresh salmon in a medium skillet, add water to almost cover, lemon juice, bay leaf and peppercorns. Cover and poach until done, 12 - 15 minutes. It should be opaque and flake easily with a fork.
Remove salmon and cut into large chunks
Roughly chop the smoked salmon
Saut onion in oil until tender
Add cabbage and saut, stirring 2 - 3 minutes.
Add white wine, chicken stock, herbs, cover and simmer 10 minutes
Dissolve cornstarch in water and add to cabbage, stirring until thickened
Remove from heat and add yogurt and stir well to combine.
Add both salmons to cabbage and stir gently.Spoon into a baking dish
Top with potatoes
Bake, 400F (200C) for 15 minutes or until the top starts to brown.