Place the onion, carrots and celery in a 9x13 baking dish.
Place the turkey legs on top of the vegetables..
In a small bowl melt 4 tablespoons of the butter.
Add all the seasonings to the butter and whisk to combine.
Pour the seasoned butter over the turkey legs.
Bake for about 45 minutes. We are not looking to cook these through, they'll cook fully in the stock .No need to worry about internal temperature, we just want to get some good color on the legs and veggies.
Make the stock
Transfer the legs and all the veggies and drippings from the baking dish to a large stock pot.
Pour in the 4 cups of stock or water.
Bring to a boil and then turn down to a simmer uncovered for an hour.
Remove the vegetables and legs from the pot.
Make the gravy
In a small saucepan melt the remaining 4 tablespoons butter over medium heat.
Once the butter is melted, whisk in the flour and allow to cook for 30 seconds.
Whisk in all of the stock.
Continue whisking over medium heat until it comes to a bubble and thickens.
Add salt and pepper to taste.
Transfer to a gravy boat or other serving jug, and serve.