Thaw out the cod or saithe. Put in a plastic bag. Mix together salt,crumbled thyme, finely chopped cloves of garlic,lime juice,oil,tomato paste,water and black pepper for the marinade. Pour the marinade over the fish. Marinate fish 1-2 hours in the refrigerator. Place the fish in an oven safe dish. Pour over the marinade. Cook in the oven at 175 c about 25 min. Serve with boiled sugar peas and potatoes or rice.