It has a stronger flavor than most white fish. Fresher is better. Prep fish in smaller pieces, season with salt and pepper. Allow to sit about 15 mins to get to room temp before cooking. Sauté diced onions in butter with salt until translucent. Place season cod in the pan on the onions at med low temp. Allow to cook for about 4 mins then flip and repeat. Do not cook all the way through. Add 1/2 and 1/2 to just cover the fish and cook gently for about 5-8 mins. Add more butter just at the end. Serve with fluffy boiled potatoes. I use Adobo green jar of mixed spices on the fish as well but that is a personal choice.