1. Melt the butter and create a roux: In a medium saucepan, melt the unsalted butter over medium heat. Once the butter is fully melted and shimmering, sprinkle in the all-purpose flour. Whisk continuously for 1-2 minutes until the mixture forms a smooth paste, known as a roux. The roux should be a light golden color and have a slightly nutty aroma, indicating the flour has cooked out its raw taste.

2. Gradually add the turkey broth: Slowly pour in the low-sodium turkey broth, about 1/2 cup at a time, whisking constantly to prevent lumps. It’s crucial to add the liquid gradually and keep whisking; this helps the roux dissolve smoothly into the broth. Continue adding broth until it’s all incorporated and the mixture is smooth.

3. Simmer and season the base: Bring the gravy mixture to a gentle simmer over medium heat, continuing to whisk occasionally. As it heats, it will begin to thicken slightly. Stir in the dried thyme, black pepper, and garlic powder. Let it simmer for 5-7 minutes, allowing the flavors to meld and the gravy to thicken further. You’ll notice it coating the back of a spoon.

4. Prepare the cornstarch slurry: In a small bowl, combine the cornstarch with the cold water. Whisk them together until the cornstarch is completely dissolved and there are no lumps. This is called a slurry, and it’s essential for thickening without creating clumps.

5. Thicken the gravy with the slurry: Slowly pour the cornstarch slurry into the simmering gravy while whisking vigorously. Continue to whisk for another 1-2 minutes. The gravy will visibly thicken as it comes back to a simmer. If you want a thicker gravy, you can make another small slurry with 1 teaspoon of cornstarch and 2 tablespoons of cold water and add it in the same way.

6. Adjust seasoning and serve: Taste the gravy and add salt as needed. Remember, if you used low-sodium broth, you will likely need to add some salt to bring out the flavors. Serve the gravy immediately while it’s hot and wonderfully smooth.