1. Peel the avocado and remove the pip. Slice the flesh and dress with the lime juice and pepper. Toast the bread slices.
2. Spread eight slices of bread with the creamy cheese, top with the avocado slices and the drained, flaked salmon and garnish with a little watercress.
3. Stack the two slices with their toppings and finish with the remaining four slices. Cut the sandwiches in half and serve.
