Yummy variation on a basic BLT or club sandwich. Just as nice on untoasted bread if it's nice and fresh. I prefer poached chicken as it stays beautifully moist & tender but you can also use grilled chicken, or leftover BBQ or roast chicken. I usually poach the chicken ahead of time when I'm making breakfast - boil water in the kettle, put it in a saucepan with the chicken and a little chicken stock powder, cover and let it sit in the hot water until lunchtime - it's perfectly cooked, but in no danger of being over-cooked and rubbery. I do hard-boiled eggs the same way (often at the same time in the same pan).