Preheat the oven to 200C/400F/gas mark 6. Place the tomatoes at one end of a baking sheet and sprinkle with the garlic and 1/4 tsp thyme. Drizzle over 1 tsp olive oil and season with salt and pepper. Roast in the oven for 15 minutes.
Place the cod fillets on a large square of baking parchment Sprinkle over the remaining thyme and olive oil. Add a squeeze of lemon then fold up to enclose the fish.
Remove the tomatoes from the oven and place the fish at the other end of the baking sheet. return to the oven for a further 10 minutes.
Check the fish is cooked, it will flake easily when done and pop back for another minute or two if required. When the fish is warm transfer to serving plates and keep warm.
Tip the tomatoes into a small bowl and mash lightly with a fork. Add and juices from the fish and stir to combine. Spoon on chunky tomato sauce top of the cod and serve immediately with vegetables of your choice.
Nutrition information is calculated usingan online nutrition database - is approximate and is meant as a guideline only. (It does not include seasoning with salt and pepper.)