Place the salmon in large baking pan, pour the white wine over the salmon, cover and bake for 1 hour.
Warm the oil in a small non-stick pan and, when it is hot, sauté the onion and garlic over a medium-high heat, stirring, until it has begun to soften. Set aside until needed.
Remove the salmon from the pan and allow it to cool.
Break the salmon into small pieces and combine it with the sour cream, onion, garlic and dill, and mix until all the ingredients are well-combined.
Lay one sheet of puff pastry on a greased baking sheet, and spread the salmon mixture over the pastry leaving a 1/2 inch border along all sides.
Top with the remaining puff pastry sheet, and crimp and seal the edges.
Brush the top of the pie with egg wash (1 egg white mixed with 1 teaspoon water) and bake it for approximately 1 hour or until the top has begun to lightly brown.
Notes: Because salmon obviously vary in size, use your culinary judgement when adding the sour cream. Add a little at a time. You don't want the filling to be too liquidy but you do want it moist. If you have extra puff pastry, you can make decorative shapes on the top of the pie.