In a large bowl, combine flour and salt. Cut in butter or lard until mixture is an even crumbly texture. Add cold water a tablespoon at a time and mix until dough comes together.

Shape the dough into a disc, wrap, and chill in the refrigerator. While pastry is chilling, prepare filling.

Wash and peel the potatoes. Cut into chunks and boil in a medium size pot of water until tender, about 12 minutes. Drain, mash the potatoes, and set aside.

Remove the skin and break the salmon into pieces. Add the salmon, onions, and poaching liquid to the mashed potatoes and mix to combine. Taste and adjust salt and pepper if needed.

Preheat the oven to 400°F.

On a lightly floured surface, divide dough in half and form two balls. Flatten one ball with your hands, and roll dough to about 12-inches in diameter, to fit a 9-inch pie pan.

Place the pastry into the pie plate and add the salmon pie filling. Gently pat the filling down to remove any air spaces.

Brush around the outer edge of the pastry with the beaten egg. Roll out the top pastry and place on top of the pie filling.

Fold the top crust under the bottom crust and pinch the edges. Brush with egg wash and cut vent holes.

Bake the salmon pie in a preheated oven for 30-35 minutes, or until the pastry is golden brown. While the salmon pie is baking, make the dill béchamel sauce.

Melt the butter in a small saucepan over medium heat. Add the flour and whisk until smooth. Gradually add milk stirring constantly. When sauce begins to thicken, add the lemon juice, dill, and salt and pepper to taste. Simmer for 2 minutes. Keep warm until ready to serve.

Remove the pie from oven and let it cool for at least 10 minutes before serving. Cut into pie wedges, drizzle with the dill sauce if desired, and serve warm.

Yield: Makes 1 pie, about 8 servings.