Luxurious salmon tart

This salmon tart has been voted an absolute knockout by everyone to whom I've served it. It is luxurious, yet healthy and easy to make.

Ingredients

4 Tbsp	Extra virgin olive oil
500 g	Flaky pastry, pre-rolled (Main)
2 Tbsp	Butter
3	Onions, sliced
2 tsp	Fennel seeds
200 g	Smoked salmon, sliced
½ cup	Creme fraiche
2 Tbsp	Horseradish
1 jar	Salmon caviar, small
1 to taste	Salt & freshly ground pepper
1 to garnish	Fresh dill, stalks removed and roughly chopped

Directions

1. Pre-heat oven to 200C. Lay the pastry in a 30cm x 40cm oven tray. Allow to rest in the fridge for at least 30 minutes if possible.
2. In a heavy frying pan, heat the olive oil and butter and add the onions.
3. Cook slowly over a gentle heat, stirring frequently until they begin to caramelise. This can take 10 to 30 minutes, depending how patient you are. Ladle the onions on to the pastry, spread evenly, then scatter the seeds over.
4. Put in the oven and raise the temperature by 10C. Bake for 15 to 20 minutes until the pastry is puffed and golden.
5. Meanwhile, stir the horseradish into the creme fraiche and refrigerate until needed.
6. Finally, cover the tart with the salmon, drizzle over the horseradish-flavoured creme fraiche, and top with the salmon caviar and the herbs.
7. Cut into individual servings and eat at once.
8. Can be served as an entree, a luncheon dish or with drinks as an appetiser.