Remove the beef tenderloin from the refrigerator and let it come to room temperature for about 30 minutes.

In a small bowl, combine the crushed espresso beans, ground cardamom, brown sugar, kosher salt, and black pepper. Mix well to create a spice rub.

Pat the beef tenderloin dry with paper towels. Rub the olive oil all over the tenderloin, ensuring it’s evenly coated. Generously apply the espresso-cardamom rub to the tenderloin, pressing it into the meat to ensure it adheres well.

Preheat your smoker to 225°F (107°C). If using wood chips, choose a flavor that complements beef, such as hickory or oak.

Place the seasoned beef tenderloin in the smoker and smoke for approximately 1.5 to 2 hours, or until it reaches an internal temperature of 135°F (57°C) for medium-rare.

While the beef is smoking, heat 2 tablespoons of butter in a skillet over medium heat. Add the sliced shallots and cook, stirring occasionally, until they are golden brown and caramelized, about 10-12 minutes. Add the fresh thyme and season with salt and pepper. Remove from heat and set aside.

Once the beef has reached the desired internal temperature, remove it from the smoker. Heat a skillet over high heat with the remaining 2 tablespoons of butter. Sear the tenderloin on all sides for about 2-3 minutes until a nice crust forms.

Transfer the seared tenderloin to a cutting board and let it rest for 10 minutes before slicing.

Slice the beef tenderloin into medallions and serve topped with the caramelized shallots and thyme butter. Optionally, sprinkle with smoked sea salt for added flavor.