In a Dutch oven, heat 2 tablespoons of extra-virgin olive oil over medium heat. Add sliced spicy smoked sausage and cook for about 5-7 minutes until browned and slightly crispy. Remove the sausage from the pot and set it aside, leaving the flavorful drippings for the next step.

In the same pot, add chopped yellow onion, diced red bell pepper, and diced celery. Sauté these aromatic veggies for 2-3 minutes, stirring occasionally, until they soften and the onion turns translucent. Add minced garlic and cook for an additional minute until fragrant.

Add 3 tablespoons of unsalted butter to the pot, allowing it to melt. Then, sprinkle in ¼ cup of all-purpose flour, stirring constantly for 2-3 minutes until the mixture is a light golden color. This roux will give your Cajun potato soup that luscious creamy texture.

Gradually pour in 4 cups of low-sodium chicken broth and 1 cup of half and half, stirring continuously to prevent lumps. Once combined, add 4 cups of cubed russet potatoes along with 2 tablespoons of homemade Cajun seasoning, salt, and pepper to taste. Bring the mixture to a gentle simmer over medium-low heat.

Reduce the heat to low, cover the pot, and let your Cajun potato soup simmer for 20-25 minutes. Stir occasionally until the potatoes are fork-tender and the flavors meld beautifully. The soup should have thickened slightly by this point.

Stir in the reserved sautéed sausage and 1 cup of shredded sharp cheddar cheese into the pot. Mix well until the cheese has melted and is fully incorporated into the soup. Taste and adjust seasoning as necessary.

Ladle the Cajun potato soup into bowls, garnishing each with fresh chopped parsley if desired. Serve hot alongside crusty bread or cornbread.