1/2 pound salt pork or bacon, cut into 1/2-inch cubes (I used salted pork belly)
2 Tbsp unsalted butter
1 medium onion, finely chopped
1 cup water or clam juice (I used an 8-oz bottle from Bar Harbor)
2.5 lbs live cherrystone or littleneck clams (or 1 lbs chopped canned or frozen - I used canned)
1 quart whole milk
1.5 lbs russet or yukon gold potatoes (I used yukon), peeled and cut into 1/2-inch cubes
2 bay leaves
salt and black pepper
1 cup heavy cream (I used a pint)
On low heat, combine salt pork and 1/4 cup water in a heavy-bottomed stock pot or Dutch oven, stirring occasionally, until water has evaporated and pork has begun to brown and crisp in spots, about 8 minutes (I cooked it for a good 20 or 30 minutes - VERY slow on low heat while I worked on getting the rest of the ingredients prepared). Add butter, onion, and celery. Continue to cook, stirring occasionally, until onions are softened but not browned (about 4 minutes). Add clam juice or water and stir to combine.
2. If using fresh clams: Add clams and increase heat to high. Cover and cook, opening lid to stir occasionally, until clams begin to open (about 3 minutes). As clams open, remove them with tongs and transfer to a large bowl, keeping as many juices in the pot as possible and keeping the lid shut as much as possible. After 8 minutes, discard any clams that have not yet begun to open. If not using fresh clams, skip ahead to step 3.
3. Add milk, potatoes, bay leaves, and a pinch of salt and pepper to the pot. Bring to a boil, reduce heat to a bare simmer, and cook, stirring occasionally, until potatoes are tender and start to break down, about 15 minutes.
4. If using fresh clams: Meanwhile, remove meat from inside the clams and roughly chop it. Discard empty shells. Transfer chopped clams and as much juice as possible to a fine mesh strainer set over a large bowl. Let clams drain, then transfer chopped clams to a separate bowl. Set both bowls aside. If not using fresh clams, skip ahead to step 5.
5. I used canned clams (because I couldn't find frozen ones) so I poured the fluid from the cans into a bowl and dumped the chopped clams into a second bowl. Once potatoes are tender, pour the entire mixture through the fine mesh strainer into the bowl with the clam juice, rapping the strainer with the back of a knife of a honing steel to get the liquids to pass through. Transfer strained solids into the bowl with the chopped clams. You should end up with a white, semi-broken broth in the bowl underneath and the chopped clams, potatoes, salt pork, and aromatics in the separate bowl.
6. Transfer liquid to a blender and blend on high speed until smooth and emulsified, about 2 minutes. Return liquid and solids back to Dutch oven. Add heavy cream and stir to combine. Reheat until simmering. Season well with salt and pepper. Serve immediately with oyster crackers.