Preheat the oven to 200°C/180°C fan/Gas mark 6.
Ensure the scallops and shells are clean and free from grit, rinse with a little cold water if needs be.
Arrange the scallops in shells onto a shallow baking tray. Add a small knob of butter on top of each scallop, sprinkle a little lemon zest and parsley and then top with breadcrumbs.
Pop the tray of scallops into the hot oven for 6-7 minutes when the scallops should be just cooked and hot through and the breadcrumbs golden and crisp.
Serve immediately in the shells with a small wedge of lemon for extra zing.