Preheat an oven to 180°C, gas mark 4.
In a food processor, blend together breadcrumbs, rosemary, Parmesan, thyme, garlic powder and lemon zest.
Season both sides of the ﬁsh ﬁllet with salt and pepper.
Arrange on a baking tray and sprinkle generously with the breadcrumb topping.
Bake for 5-7 minutes or until the ﬁsh is cooked through.