In a large pot over medium heat, combine 4 cups water with littlenecks or quahogs (adding fennel tops and an extra clove or 2 of garlic if desired). Steam clams open, discarding any unopened shells. Fine-strain and reserve the broth. Remove clams from shells (roughly chop quahogs if using), discard shells and set clams aside with additional (optional) chopped clams.

Heat a large stockpot on low heat and render the bacon, raising heat as the fat melts to help crisp. Remove bacon with slotted spoon and set aside.

Sauté onions, celery, carrots, fennel and garlic in the bacon fat about 3–5 minutes.

Add butter and melt to start the roux. Stir in the flour and cook for about 2 minutes. (If you wish to keep this soup gluten free, you may skip this step and replace it with a slurry using cornstarch or simply blend a portion of vegetables before the clams get added.) Add white wine and 4 cups reserved clam broth and stir.

Add potatoes, butternut squash and seasonings. Cook over medium-high for a steady simmer until the potatoes and squash are cooked through, approximately 15 minutes. (Add more clam broth if it doesn’t cover the vegetables by an inch.)

Lastly, add the clams, cooked bacon, leafy greens, heavy cream and fresh herbs. Raise the heat until the chowder comes to a strong simmer for 1 minute. Lower or remove from heat. Lastly, stir in the lemon juice and zest and taste for seasonings.