Tip the salmon into a bowl and mash with a fork. Add the soft cheese and cucumber and mix together, seasoning with a little black pepper.
The softened bones in canned salmon are edible. They are a useful source of calcium - essential for healthy bones and teeth.
Lay the tortillas on a work surface and spread the salmon mixture over them. Top with shredded lettuce and watercress, sprinkle with lemon juice (if using), then roll up. Slice in half and serve with extra salad, or wrap in cling film and keep chilled to eat later.
Wholewheat flour tortillas will provide extra fibre, though you could use plain or seeded wraps instead.