Bake in the oven for 20 minutes, or until the courgette is cooked
Meanwhile take a piece of kitchen foil large enough to wrap the cod steak in and lightly oil it. Place the fish on the foil and sprinkle with the lemon juice and thyme
Close up the foil parcel and place it in the oven. Bake in the oven for 20 minutes, or until the fish is cooked
When the courgette has been in the oven for 20 minutes (around 5 minutes before the fish is ready), remove from the oven, scatter grated cheese over the top and grill until the cheese bubbles. Serve with the fish