Preheat the oven to 200°C/fan 180°C/gas mark 6. Combine the sourdough crumbs, grated parmesan and parsley with 2 tbsp olive oil and freshly cracked black pepper. Season the cod, then press the sourdough crumb into one side. Place on a baking tray and cook for 12-13 minutes until the flesh flakes easily.
Cook the orzo according to the instructions on the packet. Meanwhile, heat the remaining olive oil over a medium heat. Add the garlic and lemon zest and briefly sauté until the garlic has softened.
Add the peas along with a splash of water and cook for 1-2 minutes until bright and tender. Drain the orzo and add to the peas, seasoning well and tossing to combine. Add the lemon juice and remove from the heat, then serve with the crumbed cod.