Fill a medium bowl with water and add 1 tablespoon of all-purpose flour; mix until flour is dissolved. Add the clams and allow them to sit for 30 minutes. In this time, the clams will gorge on the flour, releasing any sand and/or grit. Rinse the clams thoroughly.
Meanwhile, in a medium pot, combine the water and salt; bring to a simmer. Gently add the clams and cover, steaming the clams for 4-5 minute and removing the clams as they open. Any clams that have remained closed (I had one), discard. The water the clams were steamed in is our clam juice! Pour the clam juice through a sieve into a measuring cup. Reserve 2 cups. Next, remove the meat from each of the clams and dice. Set the clam juice and clams aside.
In a large pot or dutch oven, heat a tablespoon of olive oil. When the oil is hot, add the pancetta and cook on both sides for 3-4 minutes and until golden brown. Remove the pancetta with a slotted spoon and drain on a bed of paper towels. Next, add the onions and leeks and cook until they're translucent, about 5-7 minutes. Add the garlic and cook until fragrant, about 1-2 minutes.
Melt the butter atop the onions. Once melted, add the flour, mixing the two together and cook for 1 minute. Stir in the reserved clam juice and heavy cream; bring the mixture to a simmer and cook until thickened, about 3-5 minutes. With a piece of kitchen twine, tie the tarragon and bay leaf together. Mix in the tarragon/bay leaf gardin, potatoes, Worcestershire and hot sauce and simmer until potatoes are tender, about 10-15 minutes. Fold in the pancetta and corn. Salt to taste (I needed no additional salt), and serve warm with oyster crackers.