Serves a crowd
In a backyard fire pit, start a large fire. Continue to check the fire as you prepare the turkey. Try to build a large bed of coals.
Mince garlic cloves and chop herbs. Blend the mixture in a bowl with salt and pepper. Prepare turkey by clearing the cavity. Drizzle olive oil inside cavity and over the entire bird. Spread the garlic and herb mixture over the entire surface of the turkey as well as inside the cavity.
Place the turkey inside the oven bag and squeeze out all the air. Flatten out sections of clay and evenly cover the bagged turkey with ¾–1 inch of clay. (The more clay you add, the longer the turkey will take to cook but will also have less chance of burning.) Once the turkey is coated, wrap the clay-covered turkey in foil.
When you have a large coal bed built up, clear a turkey-shaped hole in the bed. Place the turkey on the hot coals and cover as much of the turkey with the coals as possible. Add more wood to maintain a fire on top of the turkey. Cook the turkey for 2½–3 hours, depending on the size of the coal bed, the type of wood used, and so forth. Often you will be able to smell the turkey when it is close to being done. However, make sure you check the turkey with a meat thermometer, inserting it into the thickest part of the thigh. In order to insert the thermometer you will have to chip a little hole in the clay. The turkey will be done when the thermometer reads 165°.
Use a shovel to remove the turkey from the fire pit. At this point, the clay should be quite crumbly. (Do not attempt to move or flip the turkey before this point.) Let the bird rest for 15 minutes. Then remove any remaining clay and foil. Take off the oven bag, carve and enjoy.