Melt 4 tbsp unsalted butter in a heavy saucepan over medium heat, add 1/3 cup all-purpose flour, and whisk constantly for 6 to 9 minutes until the roux is the color of milk chocolate.

Stir in the 1/2 tsp garlic powder, 1/2 tsp onion powder, 1 tsp black pepper, 1/2 tsp cayenne, 1/2 tsp smoked paprika, and 3/4 tsp kosher salt and stir for 30 seconds to bloom the spices.

Gradually whisk in the 2 1/2 cups chicken stock and 1/4 cup beef stock, bring to a boil over medium-high heat, then reduce to medium-low and simmer for 8 to 10 minutes until thick enough to coat the back of a spoon.

Remove from heat, stir in the 1 tsp Worcestershire sauce, taste for salt, then ladle over mashed potatoes or biscuits and finish with a pinch of black pepper on top.