Preparation

• One day ahead, rinse the salt cod, put it in a large bowl, and cover with cold water. Cover with plastic and refrigerate for 24 hours, changing the water several times.

  In a 4-quart saucepan, bring 6 cups of water to a boil over high heat. Add the soaked cod, and simmer gently over low heat until it flakes easily with a fork, 10 to 20 minutes, depending on thickness. Drain and cool. Remove and discard the skin, bones, and any spongy ends. Shred the cod into pieces.

  In a 6-quart Dutch oven, heat the oil over medium heat. Add the salt pork and cook, stirring occasionally, until crisp, 4 to 6 minutes. Transfer with a slotted spoon to a plate lined with paper towels. Add the onion, celery, and a pinch of salt to the pot and cook until the vegetables are tender, 3 to 4 minutes. Stir in the potatoes and corn. Add 2 cups water, the clam juice, thyme, and bay leaf. Adjust the heat as necessary to reach a simmer and cook until the potatoes are just tender, 10 to 12 minutes. Stir in the salt cod, salt pork, heavy cream, and milk. Heat to a gentle simmer, but don’t boil. Remove the bay leaf and thyme sprig, and season to taste with salt and pepper before serving.