In a food processor, combine the flour, salt, baking powder, and butter and pulse until fine crumbs form.

Transfer the crumbs to a large mixing bowl. Add the egg and cut it in with a fork, gradually adding the ice water as you go. Continue mixing until the mixture forms a smooth ball forms.

Form the dough into a disk and wrap it in plastic wrap. Chill in the refrigerator for at least 30 minutes

Preheat the oven to 360°F.

On a lightly floured surface or between 2 sheets of parchment paper, roll out the dough into an even disk, about 2 millimeters thick.

Transfer the dough to a round tarte pan, about 1 inch high and 8 inches in diameter. Poke holes in the bottom with a fork.

Place a sheet of parchment on top of the dough and fill it with pie weights or dried beans. Bake for 20 minutes, then remove from the oven a place on a wire rack to cool. Remove the pie weights.

In a medium bowl, mix together the eggs, sour cream, cheese, salt, and spices.

When the par-baked crust has cooled, arrange the salmon pieces in the bottom in a single layer. Pour the egg mixture over the salmon and then arrange the asparagus pieces on top.

Bake for another 20 to 25 minutes until the filling is set and the top is lightly golden.

Serve it warm, after allowing it to cool for a few minutes, or at room temperature.