Begin by heating a large pot over medium heat and adding the chopped bacon. Sauté until the bacon turns crispy and golden brown, about 5 minutes. Once done, use a slotted spoon to remove the bacon and set it aside, leaving the rendered fat in the pot to infuse the chowder with flavor.

In the same pot with the bacon grease, melt the butter over medium heat. Add the finely chopped onion and celery, stirring occasionally, and sauté until they become tender and translucent, around 3–4 minutes. Then, add the minced garlic and cook for an additional 30 seconds until fragrant, allowing the scents to mingle beautifully.

Next, sprinkle the all-purpose flour over the softened aromatics and stir vigorously for about 1 minute. This will create a roux that acts as a thickening agent for your creamy New England clam chowder. Ensure the flour is well incorporated and cooked before proceeding to the next step for a smooth texture.

Gradually pour in the chicken broth or clam juice while continuously stirring to prevent any lumps from forming. Keep the heat medium-high to bring the mixture to a gentle simmer. As it heats, the base will thicken and develop that rich flavor synonymous with a hearty clam chowder.

Once the broth is simmering, add the diced russet potatoes along with the salt, black pepper, and dried thyme. Stir well, and allow the pot to simmer uncovered for about 15 minutes or until the potatoes are fork-tender. This cooking process will soften the potatoes and enhance the chowder's heartiness.

Now it’s time to add the chopped clams and heavy cream to the pot. Stir gently and allow the chowder to warm through for about 5 minutes. Be careful not to let it boil, as this could cause the cream to curdle. Taste your chowder and adjust the seasonings if necessary for that perfect flavor balance.

Ladle the creamy New England clam chowder into individual bowls and garnish generously with the crispy bacon reserved from earlier. The enticing aroma and luscious texture will beckon everyone to the table. Serve warm, paired with toasted bread or oyster crackers for a delightful crunch alongside your chowder.