For this dish, I added some mushrooms for extra flavour. If you do not like mushrooms, or would like to do without the hassle, you can omit them. I served my salmon en croute with some salad by the side.

Recipe (serves 4):

750g salmon fillet, boneless
400g puff pastry block
300g asparagus
150g brown swiss mushrooms, diced
1 small red onion, chopped
1 tbsp unsalted butter
1/4 cup whipping cream
1 small sprig of thyme
3 tbsp freshly chopped dill
zest of one lemon
salt and pepper, to taste
1 egg, beaten (for glazing)

Method:

1. Preheat oven to 230°C.
2. Melt butter in a small frying pan. Add chopped onions and fry till translucent.
3. Add thyme and diced mushrooms. Fry over medium fire till mushrooms are soft, and the liquid has evaporated.
4. Season with salt and pepper. Remove the thyme sprig. Set aside.
5. Remove the bottom 1/3 of the asparagus stalks.
6. Blanch the asparagus in boiling water till soft. Upon removal from boiling water, place them in cold water immediately.
7. Using a blender, or food processor, puree the asparagus stalks. If necessary, add a tablespoon or two of water.
8. Add whipping cream, chopped dill and lemon zest to the puree. Blend and season with salt and pepper.
9. Remove the skin of the salmon. Prepare the salmon by cutting it into 4 equal parts. Season both sides of the fillet with salt and pepper.
10. Roll out the puff pastry and separate it into 8 sections.
11. On one rectangular piece of puff pastry, place one portion of mushrooms in the centre, topped by the salmon fillet and finally the asparagus puree.
12. Place another piece of puff pastry over this, and seal the sides by pressing down on it.
13. Repeat for the other 3 servings.
14. Brush with eggwash and place it on a tray lined with baking paper.
15. Bake for about 20 minutes, until the top of the pastry is golden brown.