In your largest stock pot over medium high heat, cook bacon until crispy. Remove to a paper towel covered plate. Leave all grease in pot.
Add butter. Once melted add onion, garlic, carrots, celery, salt, pepper, thyme, sage, and paprika. Saute for 5 minutes, then reduce heat to medium. Add flour and stir to combine. Let cook another 3 minutes.
Add broth and potatoes. Allow to boil and cook for 25 minutes. Potatoes should be soft but not mushy.
Remove a third of the soup to a mixing bowl and blitz with an immersion blender. (or use a blender, just use caution when blending hot items). Once mostly smooth, add corn starch and heavy cream. Blend until fully incorporated. Return to pot. Stir to combine.
Add clams, with all of their juices, along with cooked bacon and stir to combine. Let cook and thicken another 15 minutes. Serve in a bread bowl or other soup bowl. Garnish with parsley, if desired.