Trim excess fat from the beef tenderloin and make shallow transverse cuts about 2.5 cm apart across the surface.
In a small bowl, combine 2 teaspoons chili powder, 1 teaspoon salt, 1 teaspoon powdered espresso coffee, 0.5 teaspoon garlic powder, 0.5 teaspoon dried oregano, and 0.5 teaspoon ground black pepper.
Coat all sides of the steak evenly with the spice rub mixture, pressing it gently into the surface.
Heat vegetable oil in a large skillet over medium-high heat for 2-3 minutes until hot. Place the steak on the skillet, immediately reduce heat to medium, and cook for 12-14 minutes total, turning once halfway through, until the internal temperature reaches 70-75°C (158-167°F).
Transfer the steak to a cutting board and slice thinly. Serve with cilantro leaves sprinkled on top if desired.