Bake for 16–22 minutes, depending on size and thickness. (Thicker chicken breasts will take longer to cook.) A 150–200g/5½–7oz skinless chicken breast fillet will need 16–18 minutes ...
Scatter the cherry tomatoes and pine nuts (if using) on top, followed by the breadcrumbs, remaining cheddar and Parmesan. Bake for 20–25 minutes, until bubbling hot and the top is golden brown.