Preheat the oven to 450F.
In a microwave-safe bowl, combine the butter, salt, garlic, and chopped herbs. Microwave on high for 1-2 minutes or until the butter fully melts. Remove the bowl from the microwave oven, stir well, and set aside for 5 minutes to let the butter infuse with the garlic and herb flavors.
Return the bowl to the microwave oven and cook the mixture on high for another 30 seconds to ensure the butter is fully liquefied.
Strain the butter mixture through a fine sieve. Reserve the garlic and the herbs.
Place the turkey in a roasting pan, breast side up. Cover with a plastic wrap to prevent the butter from accidentally squirting out and making a mess. Fill the kitchen meat injector with the strained butter and inject the turkey breasts all over, in a diamond pattern, releasing about 1/4 - 1/3 of an ounce at a time. Reserve some butter and inject it into the thighs and drumsticks.
Rub the garlic and herb mixture and the butter from the bottom of the roasting pan all over the turkey and inside the cavity. Alternatively, you can stuff the garlic and herb mixture under the skin, similar to how I do it for my rotisserie turkey. You can see it here - https://www.youtube.com/watch?v=QkGJUiQ6FzQ.
Evenly sprinkle 1 teaspoon of kosher salt all over the turkey and pat it down to make sure the salt sticks.
If using a BBQ thermometer (highly recommended), insert the probe into the thickest part of the turkey breast and connect to the thermometer.
Roast at 450F for 10-15 minutes to get some light browning going (see notes). Gently baste with some melted butter, then drop the temperature to 325F and roast for another 2 hours and 30 minutes or so, until the internal temperature in the thickest part of the breast reaches 160F. Brush the top of the turkey with butter pan juices about an hour after dropping the temperature to 325F, and once more about 45 minutes later.
Remove from the oven and let the turkey rest for 5 minutes before slicing and serving.