Step 1

In a medium saucepan over medium heat, melt the butter. Add the onion and garlic and cook, stirring frequently, for 5 mins or until onion softens. Add the spinach and cook for 2 mins or until the spinach wilts. Add the cream cheese and season with salt and pepper. Cook, stirring, until the cream cheese melts and the mixture is well combined. Remove from heat and stir in the parmesan and breadcrumbs. Transfer to a heatproof bowl to cool completely.

Step 2

Place rack in centre of oven and preheat to 200°C (180°C fan-forced). Line a large baking tray with baking paper. Trim the pastry sheets along 1 edge so each sheet is 19cm wide. Season the salmon and place in the centre of each pastry sheet. Spread the spinach mixture evenly over the salmon to cover the top and sides. Brush the pastry around the salmon with egg. Fold pastry lengthways to enclose the filling, then fold over the short ends, pressing the edges firmly to seal. Place salmon parcels seam-side down on the lined tray. Brush pastry with remaining egg and use a small sharp knife to lightly score. Season. Bake for 30 mins or until the pastry is golden and puffed. Set aside for 5 mins to rest.

Step 3

To make the cos salad, in a small bowl, whisk mustard and lemon juice. While whisking, gradually add oil in a thin steady stream. Season. In a large bowl, toss lettuce with dressing to coat.

Step 4

Divide the salmon Wellingtons among serving plates. Season and serve with the salad.