Ocean trout en croûte

1.For puff pastry, coarsely chop 100gm butter and process in a food processor with flour and salt until fine crumbs form. Add milk and process until a dough just forms. Form into a disc, wrap in plastic wrap and refrigerate overnight to rest. Meanwhile, beat remaining butter between two sheets of baking paper with a rolling pin to soften, roll into a 15cm square, ensuring edges are even, cover with plastic wrap and refrigerate overnight. Roll out dough on a lightly floured surface to a 30cm square, stretching corners out slightly. Lay butter square in centre of pastry and turn 45 degrees. Fold corners of dough in over butter to enclose, pinch to seal, then roll out to a 35cm x 60cm rectangle. Fold one short side in to centre, fold opposite side in to meet it, then fold in half to form a book fold. Roll out to a 25cm x 75cm rectangle, repeat folding, wrap in plastic wrap and refrigerate to rest (2 hours). Repeat folding and rolling twice more, rest for another 4 hours, then repeat. Cut pastry into two pieces, wrap in plastic wrap and refrigerate or freeze until required.

2.Preheat oven to 150C. Spread leeks on a baking tray lined with baking paper, dot with butter, season to taste, cover with foil and roast until very tender (15-20 minutes), then cool to room temperature.

3.Meanwhile, wilt silverbeet leaves and stems in a large frying pan over high heat (1-2 minutes), then cool to room temperature. Squeeze out any excess moisture with a tea towel, transfer to a bowl, stir in lemon rind, season to taste and refrigerate until required.

4.Roll out each piece of pastry on a lightly floured surface to 3mm thick, place on floured trays and refrigerate to rest (30 minutes).

5.Overlap crêpes on a piece of baking paper to form a square large enough to wrap trout (3 crêpes long and 3 crêpes wide). Place leeks side to side on crêpes to form a rectangle about as large as a trout fillet. Place one trout fillet on top, season to taste, top with remaining fillet, head to tail, and season to taste. Spread with silverbeet mixture, then use baking paper to roll crêpes into a cylinder to enclose trout. Place one pastry sheet on an oven tray lined with baking paper, place trout parcel on top, then brush around trout with a wet pastry brush. Cover trout with remaining pastry sheet, press edges to seal and trim edges to form a 3cm border. Crimp edges and refrigerate overnight.

6.Preheat oven to 200C. Brush pastry with beaten egg then score with a sharp knife. Bake until pastry is dark golden and fish is cooked to your liking (30-35 minutes). To test doneness, insert a thin sharp knife into centre of fish, leave for 20 seconds, then remove and feel temperature of knife – if it’s hot the fish is cooked through. Stand for 5 minutes, then thickly slice and serve hot with lemon wedges.