1.5 pounds russet potatoes – peeled and 0.5-inch diced
2 cups whole milk
1 cup heavy cream
0.5 teaspoon black pepper
0.25 teaspoon kosher salt
fresh flat-leaf parsley – chopped (for serving)
oyster crackers – for serving
Instructions
Rinse and scrub the clams under cold running water. Place them in a large bowl of cold water for 20 minutes to help expel sand, then drain and rinse again.
In a large pot, bring 1 cup water to a boil over high heat. Add the clams, cover, and steam until most have opened, 6–10 minutes, transferring clams to a bowl as they open. Discard any that do not open.
Strain the clam cooking liquid through a fine-mesh sieve lined with a coffee filter or paper towel into a measuring cup to remove grit; you should have about 2.5–3 cups. When cool enough to handle, remove clam meat from shells and chop into bite-size pieces; set aside. Discard shells.
In a Dutch oven over medium heat, cook the diced salt pork until the fat renders and the pieces are crisp, 6–8 minutes. Use a slotted spoon to transfer the cracklings to a small bowl; leave the rendered fat in the pot.
Add the butter to the pot. Stir in the onion and celery and cook over medium heat, stirring occasionally, until softened and translucent but not browned, 6–8 minutes.
Sprinkle in the flour and cook, stirring constantly, until the flour is foamy and no longer raw, 1–2 minutes.
Gradually whisk in the reserved clam liquor and the bottled clam juice, scraping up any fond. Add the bay leaf, thyme sprig, and diced potatoes. Bring to a simmer, then reduce heat to maintain a gentle simmer and cook until the potatoes are just tender, 12–15 minutes.
Reduce the heat to low. Stir in the whole milk and heavy cream and heat gently until steaming but not boiling, 3–5 minutes. Add the chopped clams and reserved salt pork cracklings and cook just until warmed through, 1–2 minutes. Season with black pepper and the kosher salt, tasting and adding more salt if needed. Remove and discard the bay leaf and thyme sprig. Let the chowder rest off heat for 5 minutes to settle.
Ladle into warm bowls and serve hot, topped with chopped parsley (for serving) and oyster crackers (for serving).