Put the cod in a deep dish, add cold water to cover and let it soak for 2 days in the refrigerator in order for it to plump up and change the water several times. Rinse and dry the fish and cut it into 2 inch chunks.
Dredge the fish in flour, shaking off the excess. In a large skillet, heat 2 tablespoon of the butter and olive oil. Add the fish pieces and brown them well on all sides over medium high heat.
Sprinkle the fish with the minced garlic and parsley and stir the mixture gently. Cut the remaining 2 tablespoons butter into bits and add it to the pan. Sprinkle the fish with salt and pepper and pour over the lemon juice. Serve immediately.
