Lightly toast the bread until it’s slightly crisped but not browned. Spread both slices with butter, then cover one slice with mayonnaise, and the other with the soft cheese.
Scatter the lettuce over the mayonnaise. Thinly slice the chicken and arrange it on top in an even layer. Season with salt.
Spread the Branston over the cream cheese, then sandwich it on top of the chicken. Cut in half to serve.
