Drain the potatoes and set them aside while preparing the soup base.

In a large saucepan over medium heat, melt the butter until it begins to bubble slightly.

Whisk the flour into the melted butter, stirring constantly to form a smooth paste that smells slightly nutty.

Slowly pour in the chicken broth while whisking to prevent lumps, creating a smooth and slightly thickened mixture.

Add the cold water and continue stirring as the soup base begins to simmer and thicken.

Stir in the heavy cream and season with salt and black pepper for a rich and silky texture.

Add the cooked potatoes to the pot and gently stir so the cubes remain intact.

Sprinkle in the shredded cheddar cheese and stir until it melts completely into the soup.

Fold in most of the crumbled bacon and allow the soup to simmer for several minutes until everything is heated through.

Taste and adjust seasoning, then ladle the soup into bowls and garnish with green onions and extra bacon.