Warm the stock: Bring the stock to a simmer in a medium saucepan over medium heat.
3½ cups low-sodium turkey stock or chicken stock
Brown the butter: In a stainless steel skillet, melt the butter in a medium saucepan over medium heat. Continue cooking, stirring or swirling the pan occasionally, until the butter foams and the milk solids turn light golden brown and smell nutty, ~5 minutes Start Timer. (Use my brown butter post for reference). Watch closely to prevent burning. Remove the pan from the heat briefly. 6 Tbsp. unsalted butter
Make the roux: Reduce the heat to medium-low, return the brown butter to the burner, and whisk in the flour until smooth. Cook, whisking frequently, for 2-3 minutes Start Timer, until the mixture is golden brown and smells lightly toasted.
6 Tbsp. all-purpose flour
Add the stock: Slowly pour in about 1/2 cup of the warm turkey stock in a steady stream, whisking constantly until smooth. Gradually whisk in the remaining stock, making sure there are no lumps.
Season the gravy: Whisk in the Worcestershire sauce, soy sauce, onion powder, garlic powder, black pepper, and poultry seasoning. Add the thyme sprigs, rosemary sprig, and chopped sage.
1 tsp. Worcestershire sauce, 1 tsp. low-sodium soy sauce, 1/2 tsp. onion powder, 1/2 tsp. garlic powder, 1/2 tsp. freshly cracked black pepper, 1/4 tsp. poultry seasoning, 2 sprigs fresh thyme, 1 small sprig fresh rosemary, 1-2 tsp. fresh sage
Simmer: Bring the gravy to a gentle simmer over medium heat. Reduce the heat to medium-low and cook for ~8 minutes Start Timer, stirring frequently, until the gravy has thickened to your desired consistency. It should be smooth and thick enough to coat the back of a spoon. If the gravy becomes too thick, whisk in additional warm stock, a splash at a time.
Finish and adjust: Remove and discard the thyme and rosemary sprigs. Taste the gravy and season with kosher salt as needed.
Kosher salt
For extra richness: Remove the saucepan from the heat and whisk in 1 Tbsp. cold butter until melted and incorporated. Serve warm over turkey and mashed potatoes.
1 Tbsp. cold unsalted butter