If not already trimmed, remove any silver skin and excess fat from the beef tenderloin. Pat the tenderloin dry with paper towels.

In a small bowl, combine the kosher salt, black pepper, garlic powder, and smoked paprika. Rub this seasoning mix evenly all over the beef tenderloin.

Drizzle the olive oil over the tenderloin and gently rub it in. Let the seasoned tenderloin rest at room temperature for 30 minutes. This allows the flavors to penetrate the meat and helps the tenderloin cook more evenly.

Fill the firebox with charcoal and light it up using lighter cubes. Once the charcoal is lit, add your wood chunks (hickory and applewood for this recipe) on top of the coals.

Place the heat deflector inside the Egg to set up for indirect cooking. Preheat the Big Green Egg to a steady 250°F.

Once the Egg reaches the desired temperature, place the beef tenderloin on the grate, ensuring it's over indirect heat. Close the lid and let the magic begin.

Insert a meat thermometer into the thickest part of the tenderloin. Smoke the beef until the internal temperature reaches 130°F for medium-rare, which should take around 1.5 to 2 hours.

Prepare the Garlic Herb Butter (optional): While the beef is smoking, mix the softened butter with minced garlic, rosemary, thyme, lemon zest, and a pinch of salt and pepper. Set aside.

Once the tenderloin reaches the desired internal temperature, remove it from the grill. Tent it with aluminum foil and let it rest for 10-15 minutes.

Optional sear: If you prefer a crusty exterior, crank up the Big Green Egg to high heat or use a hot cast iron skillet to quickly sear the tenderloin for 1-2 minutes on each side.

Once the beef tenderloin has rested, slice it into 1-inch thick pieces. Brush with the prepared garlic herb butter if using.