Peel and dice the potatoes into bite-sized pieces, cover with water in a pot, bring to a boil, reduce to simmer and cook until fork-tender for about 15-20 minutes. Drain and set aside.

In a large pot, combine chicken stock, diced sweet yellow onion (if using), salt, and black pepper. Simmer for about 20 minutes on medium heat.

Melt butter in a separate saucepan over medium heat. Whisk in flour gradually, stirring until smooth and bubbling for about 2-3 minutes.

Add the roux to the broth while whisking continuously until the soup thickens slightly, about 5 minutes.

Stir in heavy whipping cream and allow the mixture to simmer on low heat for an additional 20 minutes, stirring occasionally.

Add the boiled potatoes back into the pot and gently fold them into the creamy broth, warming for about 5 minutes.

Ladle the soup into bowls and top with extra cheddar cheese, crumbled bacon, and diced green onions before serving.