Light your charcoal in the KUDU and let them burn to embers with a layer of white ash.
Sprinkle the ribeyes with olive oil and add a generous amount of salt ad pepper.
Twist and bend the rosemary to open it up.
Smash each garlic clove (5-10)
Chop the mushrooms into 1 inch pieces.
Adjust your cast iron skillet height over the embers at high heat. To locate high heat, place your hand over the embers and find the height you can count to 2 before having to remove your hand from the flame (approx. 600 degrees).
Move your KUDU cast iron pan to that height and let it heat up for 5 minutes.
Add your ribeyes creating a nice crust on the first side.
Flip the ribeyes and add a spoonful of duck fat.
Move the cast iron up to medium-heat or the height you can count to 5 before having to remove your hand.
Add the crushed garlic, mushrooms and rosemary.
Add a spoonful of butter.
As it melts stir over the steaks and move the garlic and mushrooms around to cook evenly.
Remove when you reach the desired temperature of your ribeye.
Allow to sit and rest.
Remove and serve.