Cook the Bacon: In a large pot over medium heat, cook the chopped bacon until crispy. Remove with a slotted spoon and set aside, leaving the bacon fat in the pot.
Sauté the Vegetables: Add butter to the pot, then stir in the onion, celery, and carrot. Cook for about 5 minutes until softened. Add garlic and cook for another 30 seconds.
Simmer the Chowder: Stir in the corn, potatoes, chicken broth, salt, thyme, and black pepper. Bring to a boil, then reduce heat and let simmer for 15 minutes until the potatoes are tender.
Add the Milk: Pour in the whole milk and stir well. Simmer for another 5 minutes, making sure not to boil.
Blend for a Creamier Texture (Optional): Use an immersion blender to partially blend the chowder, leaving some chunks for texture.
Serve & Garnish: Ladle into bowls, top with crispy bacon and fresh chives, and enjoy warm!