Initial Sauté: Heat a generous tablespoon of olive oil in a voluminous pot or a Dutch oven. Add the kielbasa sausage and sear for 4-5 minutes over medium heat until they achieve a delightful crispiness. Use a slotted spoon to transfer the sausage to a separate plate; we'll bring them back soon.

Veggie Softening: In the residual sausage-infused oil, sauté your onion, carrot, and celery for about 5 minutes until they surrender their crunch and become tender.

Aromatics Unleashed: Stir in the minced garlic and red chili flakes. Let this flavorful medley cook for an additional minute—just enough to permeate the air with their fragrance.

The Boiling Point: Introduce the cubed potatoes to the pot, and pour in your chicken stock. Elevate the heat to achieve a rolling boil. Then, lower it and let the concoction simmer under a lid for 10-12 minutes or until the potatoes yield easily to the stab of a fork.

Milk Tempering: Extract a ladle of your hot soup and combine it with the full-fat milk in a separate bowl. This technique tempers the milk, preventing it from curdling when introduced to the hot environment of the pot. Now, reunite the sausage with the soup.

Cheese Fusion: Time for cheese! Sprinkle in the grated cheddar and stir until it melds into a seamless, gooey wonder.

Final Simmer & Season: Allow your soup to simmer for an additional 2-3 minutes. It will thicken slightly. Toss in the chopped parsley for that burst of color and freshness. Season with salt and pepper as your taste buds dictate.

The Grand Finale: Ladle your creamy, savory, slightly spicy Kielbasa and Potato Soup into bowls. Add an optional flourish of extra cheddar on top if your heart desires.