In a large pot, melt the butter over medium heat.
Add the minced garlic, chopped onion, celery, and carrots.
Sauté until the vegetables are tender.
Stir in the basil, oregano, and thyme to release their aroma.
Pour in the clam stock and bring the mixture to a boil.
Add the diced potatoes and simmer until they are tender.
Mix the all-purpose flour with a bit of the milk to form a smooth paste.
Gradually stir the paste into the pot to thicken the chowder.
Gently add the clams and simmer for a few more minutes.
Stir in the remaining milk.
Continue to cook until the chowder is thoroughly heated.
Serve hot.