Rachel Allen's rillettes of fresh smoked salmon with melba toast recipe

INGREDIENTS

• 75 butter, softened
• g smoked wild or organic Irish salmon
• 200 water
• g skinless fresh salmon fillet
• 1 freshly ground pepper and nutmeg
• tsp squeeze lemon juice, to taste
• 200 slices medium-cut white bread from a large sliced loaf
• g cucumber, thinly sliced (unpeeled)
• 1 small onion, thinly sliced
• pinch caster sugar
• 1 salt