Clean, wash and drain the spinach. Peel and finely chop the onion and garlic. Fry them in hot fat. Let the spinach collapse on top. Season with salt and pepper, then drain well.
Wash the fish fillets and dab them dry. Sprinkle salmon with lemon juice, salt. Dice cod finely. Puree finely with lime juice and crème fraîche. Season with salt and pepper. Line a box form (25 cm long; 9 cm wide) with baking paper and puff pastry, letting the dough overlap.
Alternately layer salmon fillet, spinach, cod farce, spinach and salmon. Whip the dough over the filling. Spread everything with whisked egg yolk and sprinkle with pine nuts. Bake in the preheated oven (electric cooker: 225 ° C/ gas: level 4) for approx. 45 minutes.
Cover with foil in between. Then cool in the mould for approx. 30 minutes, remove and leave to rest for a further 2 hours. Serve pâté with mixed salad. Makes about 10 pieces.