Begin by peeling and dicing the potatoes into bite-sized pieces. In a large pot, cover the diced potatoes with water and bring it to a boil over medium-high heat. Let them cook for about 15–20 minutes, or until fork-tender, then drain them and set aside.

In a separate large pot, combine the chicken stock, diced yellow onions (if using), salt, and pepper. Bring this mixture to a gentle simmer over medium heat, allowing it to cook for about 20 minutes.

While the broth simmers, melt the butter in a saucepan over medium heat. Once melted, whisk in the flour, cooking it for about 2 minutes until bubbly and lightly golden, forming a roux.

Gradually whisk the roux into the simmering broth, ensuring you stir continuously to prevent any lumps from forming. Keep stirring until the soup begins to thicken, taking approximately 5–7 minutes.

Next, slowly pour in the heavy whipping cream while stirring gently. Allow the soup to continue simmering for another 20 minutes.

Introduce the cooked diced potatoes back into the pot, stirring gently to distribute them throughout the soup. Let the flavors meld together for a few minutes.

Ladle the soup into bowls, and generously top each serving with shredded cheddar cheese, crispy bacon bits, and finely chopped green onions.