Add all of the ingredients for the tandoori marinade except the yoghurt to a mini blender and blend to a smooth paste.
Add the paste to a medium bowl and mix it with the yoghurt. Then throw in the cod and toss it around to coat it well. Cover with cling film and allow to marinate for at least 2 hours, up to 24 hours.
Preheat an oven to 220°C or 450°F or an air fryer to 200°C or 390°F. If you are cooking this in the oven, place the fish on a baking tray and cook it for 18-20 minutes or until the internal temperature reaches 57-60°C (135-140°F). If you are cooking this in an air fryer, cook for 12-15 minutes or until the internal temperature reaches the same figure.
Notes
If you are cooking this in an air fryer cutting a small piece of baking parchment to the same size as the fish to place it on can help reduce the washing up.