Wash and scrub the potatoes, then dice them into small, even cubes.
Place the potatoes in a large pot and cover them with chicken stock. Bring to a boil and cook for about 10 minutes, until they are mostly tender but not fully soft. Drain and set aside.
In a large Dutch oven or soup pot, melt the butter over medium heat.
Add the flour and whisk continuously for 1–2 minutes until smooth and lightly cooked.
Slowly pour in the half-and-half and milk while whisking to prevent lumps. Continue whisking until the mixture is smooth and begins to thicken slightly.
Stir in the melted cheese and whisk until fully combined and creamy.
Add the cheddar cheese soup and mix until the soup base is smooth and rich.
Stir in the garlic powder, black pepper, and hot sauce, adjusting to taste.
Add the cooked potatoes to the pot and stir gently to combine.
Cover and cook over low heat for about 30 minutes, stirring occasionally, until the soup is thick and the potatoes are fully tender.
Taste and adjust seasoning if needed before serving.
Serve hot, topped with shredded cheddar cheese, crumbled turkey or beef bacon, and fresh chives.