Place an oven rack in the lowest position (with room above to fit the turkey) and preheat the oven to 350 degrees F.

Remove any turkey parts from the cavity and set aside in the fridge or discard.

Pat the turkey dry on the inside and out with paper towels.

Season the cavity with 1 teaspoon salt and stuff the cavity with 2 sprigs of thyme, sage, half of the onion wedges and garlic.

In a small saucepot, place the the butter, lemon zest, lemon juice and thyme. Heat until butter is just melted. Brush the turkey with the melted butter mixture.

Season the outside of the turkey well with 4 teaspoons salt.

Place the remaining onion wedges in the bottom of a roasting pan. Place the roasting rack in the pan, making sure it is level.

Place the turkey to the rack, tuck the wings back under the body and tie the legs together with kitchen twine.

Roast for 2 hours and 30 minutes, basting with pan drippings every 30 minutes if desired.

Cook until a thermometer inserted in the thickest part of a thigh measures 165 degrees F, about 2 1/2 hours.

Allow to rest for 30 minutes before carving.

Meanwhile make the gravy.

To make the gravy, remove the turkey from the roasting pan (or slow cooker for a turkey breast), pour the contents through the fine mesh sieve over a bowl, so that the drippings end up in the bowl. Discard the solids.

In a small bowl, place the 1 cup cold broth Sprinkle the gelatin powder over the broth. Set aside to dissolve.

Place the Turkey drippings and rest of the broth in a saucepan over high heat. Bring to a boil, then lower the heat to a simmer for about 20 minutes, until the gravy has reduced by half.

Add the dissolved gelatin mixture into the pan, whisking often, until dissolved.

Allow the gravy to cool from hot to lukewarm - it will thicken as it cools. It may form a film on top, but just whisk it and it will go away. It will gel and be too thick if it gets completely cold - just reheat it to make it pourable again.