Place a large pot or rondeau on the stove and add 3 cups water. Bring the water to a boil and add the clams. Cook until the clams pop open. Though it is important to stir the clams as they cook, take care because the shells are fragile and break easily. Put the clams in a colander and reserve the cooking liquid. Shell the clams; discard the shells and reserve the clam meat and the liquid separately.
Add the bacon to another large pot and cook over medium heat until crispy. Drain the bacon with a slotted spoon onto a paper towel, dust with Aleppo pepper and set aside. Add the butter to the bacon fat in the pot and quickly cook the celery, about 1 minute. Sprinkle with salt and black pepper. Remove the celery with a slotted spoon and set aside.
Add the garlic, leeks and onions to the pot and sprinkle with salt and black pepper. Cook until the vegetables become tender and translucent, 3 to 5 minutes. Add the vermouth. Continue to cook until almost all of the liquid has evaporated, 8 to 12 minutes.
Meanwhile, in another large pot, combine the cream, thyme, potatoes and bay leaves. Bring the mixture to a gentle simmer and cook until the potatoes are tender, 5 to 8 minutes. Sprinkle with salt and black pepper. Add a splash of hot sauce and Worcestershire. Stir to blend. Taste for seasoning.
There is a good chance there will be grit in the clam cooking liquid. Strain it and add it to the onion/leek mixture. Stir to blend. Taste for seasoning. Combine with the potato mixture. Add the clam meat, reserved celery, tarragon and dill. Remove and discard the bay leaves. Add the marsala. Taste for seasoning. Add more cream and water if needed. Top with the bacon just before serving and serve with the Baked Bread.
Cook's Note: When you strain the clam liquid, line the strainer with cheesecloth to catch any remaining grit.
Baked Bread for Clam Chowder Dipping:
Preheat the oven to 350 degrees F. Arrange the bread on a baking sheet in a single layer. Melt the butter in a small skillet over low heat and add the garlic. Sprinkle with salt and white pepper. Heat gently for 1 minute. Use a pastry brush to coat the bread slices with the butter. Pour any remaining butter into the bottom of the baking sheet. Dust the bread with the paprika and dill seeds. Place the baking sheet in the center of the oven and bake until the slices are browned and crispy, 12 to 15 minutes. Remove and cool for a minute before serving alongside the soup.
Active Time: 50 minutes Total Time: 1 hour 45 minutes