Preheat the oven to 200°C (180°C fan assisted) Gas Mark 6. Unroll the pastry sheet onto a baking sheet.
Spoon the rice down the middle third of the pastry. Flake over the salmon, dot over the olives and pepper. Scatter over the parsley and sundried tomatoes, then finally, season.
Brush the pastry around the filling with some egg, then trim a square of pastry from each corner and discard. Use a knife to slice the two long sides into strips, fanning out from the filling. Fold the top and bottom ends of pastry over the filling, then alternate criss-crossing over the pastry strips to weave a plait over the top of the pie.
Brush all over with more egg and bake for 25 minutes until golden, puffed and piping hot in the centre. Slice and serve with the lemon wedges.