In a large stock pot, combine 4 cups of chicken broth, 2 cubed red potatoes, 1 diced celery stalk, 2 sliced carrots, 1 diced onion, and 1 sliced leek. Season with sea salt and pepper and bring to a simmer.

Cook for 25-30 minutes, until vegetables are tender and the broth is fragrant, stirring occasionally.

In a separate saucepan, melt 4 tablespoons of unsalted butter over medium heat. Whisk in 4 tablespoons of gluten-free flour, stirring continuously for about 2 minutes.

Gradually add 2 cups of whole milk or half-and-half, whisking until smooth and thickened, about 5 minutes.

Reduce heat to low and stir in 2 cups of shredded sharp cheddar cheese until melted.

Pour the cheese sauce into the pot with the vegetable mixture and stir to combine. Add in 2 cups of cubed cooked ham and heat through for about 5 minutes.

Serve garnished with diced green onions if desired.