1 lemon, zest only
dressed green salad leaves, to serve
1 tbsp chopped fresh tarragon leaves
12 fresh lasagne sheets, cut into 12.5cm x 7.5cm/5in x 3in squares, blanched
salt and freshly ground black pepper
butter, for greasing
250g/9oz cheddar, grated
100ml/3Β½fl oz double cream
1 free-range egg yolk
300²µ/10Β½΄Η³ϊ ricotta, drained
85g/3oz canned salmon, drained
100²µ/3Β½΄Η³ϊ smoked salmon, finely chopped