Begin by dicing russet or golden potatoes into uniform cubes. In a large pot, bring salted water to a boil over medium-high heat. Carefully add the diced potatoes and cook for 15 to 20 minutes, or until fork-tender. Once cooked, drain the potatoes and set them aside.

Using the same pot, combine chicken stock, diced sweet yellow onions (if using), a dash of salt, and ground black pepper. Bring to a simmer over medium heat for about 20 minutes.

In a separate saucepan, melt ¼ cup of unsalted butter over medium heat. Whisk in ¼ cup of all-purpose flour, stirring constantly for 2 to 3 minutes until golden and bubbly.

Gradually add the roux to the simmering stock, whisking continuously to prevent lumps. Keep stirring for about 5 minutes, or until the mixture thickens.

Stir in 1 cup of heavy whipping cream thoroughly into the mixture. Lower the heat and allow the soup to simmer gently for 20 minutes, stirring occasionally.

Gently add the drained, cooked potatoes into the soup, stirring well to combine. Heat for another 5 minutes to enhance flavor.

Ladle the soup into bowls and top with crumbled bacon, shredded cheddar cheese, and chopped green onions. Drizzle with extra cream if desired.