Combine white wine and shallots in a saucepan; bring to a boil. Simmer until shallots are tender, about 2 minutes.
Add salmon pieces and poach until barely opaque, about 2-3 minutes.
Remove salmon, drain on a towel-lined baking sheet.
Strain wine, reserving shallots. Refrigerate salmon and shallots to cool.
Combine cooled salmon, shallots, smoked salmon, chives, mayonnaise, and lemon juice in a bowl.
Gently stir until combined; season with salt and pepper.
Serve cold with toasted baguette slices and extra chives.
