Finely dice the onion into 1/4-inch pieces and celery stalks, mince the garlic, and chop the fresh parsley and thyme. While prepping, preheat your oven to 375°F and place the sourdough bread bowls on a baking sheet. Toast them for 8-10 minutes until they're warm and slightly crispy on the outside—this prevents them from getting soggy when filled. Set the bread bowls aside to cool slightly.

Heat the bacon grease in a large pot over medium heat. Add the diced onion, celery, and fresh thyme sprigs, cooking for 2-3 minutes until the vegetables begin to soften and release their aromatics. Add the minced garlic and cook for 1 minute more until fragrant. I find that this slow start really develops a sweet, savory foundation that makes the whole soup taste richer.

Pour in the clam juice and chicken broth, then add the peeled and cubed potatoes, bay leaf, salt, and black pepper. Bring everything to a boil, then reduce heat to medium and simmer for 12-15 minutes until the potatoes are tender but still hold their shape. While the potatoes cook, you can prepare the roux in the next step.

While the potatoes simmer, melt the unsalted butter in a separate saucepan over medium heat. Once melted, whisk in the all-purpose flour to form a thick paste (this is your roux), stirring constantly for 1-2 minutes to cook out the raw flour taste. Gradually add the heavy cream while whisking continuously until you have a smooth, thick cream sauce with no lumps. This thickener will give the chowder its signature creamy, luxurious texture.

Once the potatoes are tender, slowly pour the cream mixture from Step 4 into the pot with the broth and potatoes, stirring gently to combine everything evenly. Add the minced clams and whole clams, then simmer for 2-3 minutes just until the clams are heated through—don't overcook them or they'll become tough. Remove from heat and stir in the Worcestershire sauce, fresh lemon juice, and chopped parsley. I always taste the soup at this point and add an extra squeeze of lemon if it needs brightness, as it really lifts all the briny, savory flavors.

Ladle the hot clam chowder into each toasted bread bowl from Step 1, filling them generously. The warm soup will soften the bread slightly while the toasted exterior keeps it from falling apart. Serve immediately while everything is piping hot.