Heat a large Dutch oven over medium-high heat. Add the ground beef and cook for 7–8 minutes, breaking it into small crumbles, until browned with no pink remaining.

Drain excess fat, leaving about 1 tablespoon in the pot, then add the diced onion and celery. Cook for 4–5 minutes, stirring occasionally, until the vegetables soften and the onion is translucent.

Stir in the minced garlic and cook for 30 seconds until fragrant.

Pour in the chicken broth and add the diced potatoes. Bring to a boil, then reduce heat to medium and simmer uncovered for 12–15 minutes, or until the potatoes are fork-tender.

While the potatoes cook, melt the butter in a small saucepan over medium heat. Whisk in the flour and cook for 1–2 minutes to form a roux.

Slowly pour the milk into the roux, whisking constantly. Cook for 3–4 minutes until the mixture thickens enough to coat the back of a spoon.

Pour the milk mixture into the soup pot, stirring to combine. Reduce heat to low, add the cubed Velveeta and shredded cheddar, and stir gently for 3–4 minutes until all cheese is fully melted.

Add salt, black pepper, paprika, garlic powder, and dried parsley. Stir in the sour cream until completely blended, then taste and adjust seasoning as needed.

Remove the pot from heat and let the soup rest for 5 minutes. Ladle into bowls and garnish with desired toppings such as diced pickles, crumbled bacon, and extra cheese before serving.