Create the Roux: In a Dutch oven over medium heat, melt the bacon grease. Stir in the flour and cook for a couple of minutes to form a roux.
Add Liquid: Slowly pour in the chicken broth while stirring constantly to combine with the roux.
Boil Vegetables: Add the potatoes, carrots, salt, and pepper. Cover and cook over medium to medium-high heat for 15 to 20 minutes until the vegetables are tender.
Incorporate Aromatics: If using dried onions, garlic, Italian seasoning, and parsley, add them after the first 15 minutes of boiling. (Note: If using fresh onions, sauté them in the bacon grease at the very beginning) .
Final Simmer: Add the cubed ham, corn, and heavy cream. Stir well and let the chowder simmer on low for about 15 minutes to allow flavors to meld and the corn to heat through.
Serve: Ladle into bowls and add optional toppings like cheese, bacon, and green onions if desired.