1. Sauté the Aromatics: In a large pot, melt the butter over medium heat. Add the onion and cook until soft, about 5 minutes. Stir in the garlic and cook for 1 minute, until fragrant.

2. Make the Roux: Sprinkle the flour over the onion mixture and stir, cooking for 1-2 minutes to remove the raw taste of the flour.

3. Add Liquids and Potatoes: Gradually whisk in the broth, then stir in the milk, cream, and potatoes. Bring the mixture to a gentle boil, then reduce the heat and simmer until the potatoes are tender, about 15-20 minutes.

4. Mash Slightly: Use a potato masher to lightly mash some of the potatoes in the pot, creating a creamy texture while leaving some chunks.

5. Add Cheese and Herbs: Stir in the shredded cheddar cheese until melted, then mix in the parsley, chives, thyme, salt, pepper, and optional cayenne or paprika. Adjust the seasoning to taste.

6. Serve: Ladle the hot soup into bowls and garnish with crispy bacon, extra cheese, sour cream, or fresh chives, if desired.