Set your EGG for indirect cooking, with the convEGGtor at 425°F/218°C with the cast iron skillet in the EGG preheating.

In the cast Iron skillet, add all of the ingredients for the duxelles. Cook for 30 minutes or until the water has evaporated. Make sure to stir often to ensure an even cook. Remove the mixture from the cast iron skillet and set aside to cool.

Liberally season the beef with salt and Steakhouse Seasoning. Using a clean cast iron skillet with 1 tablespoon (15 ml) of olive oil, sear the beef on each side for 1-2 minutes, making sure to sear the ends as well. As the last side is searing, add 1 tablespoon (15 ml) Roasted Garlic & Herb Banner Butter and coat the beef. Remove the cast iron skillet from the EGG. Immediately coat the beef with Dijon mustard and set aside to cool.

On a piece of plastic wrap (use two pieces and overlap if needed). Lay the prosciutto out in strips going away from you on the plastic wrap, with enough strips to cover the width of the beef. Make sure there are no gaps in the prosciutto. Evenly spread the duxelles across the prosciutto leaving about an inch around the edges. Lay the beef on the duxelles at the end of the prosciutto closest to you and, using the plastic wrap to help, roll the prosciutto around the beef. Tuck the ends of the prosciutto tightly under the roll, then continue to roll the beef away from you keeping the plastic wrap on the outside of the wrap until you reach the end of the prosciutto pieces. Roll tightly into the plastic wrap, set in the refrigerator for 20 minutes.

Set your EGG for indirect cooking, with the convEGGtor, at 425°F/218°C with the baking stone in the EGG preheating.

Remove the beef from the refrigerator and remove the plastic wrap. Wrap the beef in the crepes and then roll up into puff pastry. If two sheets of puff pastry are needed, then connect with egg wash. Once the beef is tightly rolled in the puff pastry use the egg wash to seal the puff pastry closed and cut off any excess dough. Roll into plastic wrap as tight as possible and put it into the refrigerator for 20 minutes for the beef wellington to set up.

Remove the beef wellington from the refrigerator. Remove the plastic wrap. If desired, add any remaining puff pastry as a design to the top or sides to the beef wellington. Use the remaining egg wash as a binder for the design. Coat the entire beef wellington with egg wash, including the bottom. Gently add rosemary leaves to the top of the beef wellington. Season all sides of the beef wellington with kosher salt.

Place a piece of parchment paper between the beef wellington and the baking stone. Bake the beef wellington for 30-40 minutes, or until the puff pastry is golden brown and the internal temperature of the beef reaches 125°F/51°C.

Remove from the EGG, let rest for 10 minutes. Slice, and serve with sauce!

In the cast Iron skillet, add all of the ingredients for the duxelles. Cook for 30 minutes or until the water has evaporated. Make sure to stir often to ensure an even cook. Remove the mixture from the cast iron skillet and set aside to cool.

After searing the beef, deglaze the cast iron skillet with red wine, leave it for 30 seconds and then carefully transfer to the cast iron sauce pot. Add onion, garlic, Worcestershire sauce and beef stock.

Place the cast iron sauce pot with the sauce ingredients on the EGG to cook. Remove the sauce once it has reduced by half.