Heat 2 tablespoons of oil or butter in a large saucepan over medium-high heat until shimmering. Add diced onion, carrots, and celery, then sauté for about 8-10 minutes until the vegetables are tender and the onion is translucent.

Stir in 3 minced garlic cloves and 1 teaspoon of fresh thyme, allowing them to cook for about 1 minute until aromatic. Sprinkle in 2 tablespoons of flour, stirring constantly for about 2-3 minutes.

Gradually pour in 4 cups of ham or chicken broth, deglazing the pan, then stir in 1 cup of milk and 2 cups of diced potatoes, bringing the mixture to a gentle boil.

Reduce to medium-low and let the chowder simmer for about 10-12 minutes until the potatoes are fork-tender.

Add 2 cups of diced ham and 1 cup of corn into the chowder. Continue cooking for an additional 5 minutes until everything is heated through.

Ladle the chowder into warm bowls and garnish with fresh herbs or crispy bacon if desired.