Thanks to True Aussie Beef & Lamb for the steak that inspired this recipe.
Set the EGG for direct cooking without the convEGGtor at 500°F/206°C; add the Dual-Sided Cast Iron Plancha Griddle to the EGG to preheat.
Pat the steaks until dry. Season on all sides with Ancho Chile & Coffee Seasoning and rest the steaks at room temperature for 30 minutes.
Heat the butter or oil on the plancha. Carefully add the steak and cook, flipping once, until a golden-brown crust starts to develop, about 3-4 minutes total. Remove from the heat to rest.
Add the mushrooms and herbs to the griddle and sauté until golden brown. Push mushrooms to the side and add the steaks back into the griddle, basting with butter or oil. Continue searing and basting until an instant-read thermometer inserted into the thickest part of the steak registers 120–125°F/49–52°C for medium-rare, 6 to 10 minutes total.
Remove the cast iron griddle from the EGG and spoon mushrooms over the steak and let rest 5 to 10 minutes before serving. Serve with your favorite veggies, seasonal salad, or roasted potatoes.