Melt butter in a large pot over medium-high heat, then add diced onion. Cook 4-5 minutes or until onions are soft.
Add garlic to the pot and cook another minute or so, until fragrant.
Sprinkle the flour over the onion mixture and stir constantly for two minutes.
Slowly stir in chicken broth, half and half, and 1 cup clam juice (juice from about two cans of clams).
Add salt, black pepper, dried thyme, and dried oregano.
Bring to a boil, then reduce heat to low and simmer for 20 minutes.
Add the diced potatoes and simmer another 20 minutes, or until the potatoes are tender.
Add the clams and cook another 5 minutes, until clams are heated through.
Spoon into bowls and top with desired toppings, such as crumbled bacon, minced fresh parsley, and oyster crackers.
