Prepare the Marinade: In a small bowl, combine minced garlic, chopped rosemary, smoked paprika, salt, and black pepper. Mix well to form a paste.

Season the Steaks: Rub the garlic and rosemary mixture all over the filet mignon steaks. Allow the steaks to marinate for at least 30 minutes at room temperature.

Make the Bone Marrow Butter: In another bowl, mix the softened butter with the cooked bone marrow until well combined. Set aside.

Preheat the Grill or Skillet: If using a grill, preheat it to high heat. If using a skillet, heat a tablespoon of olive oil over medium-high heat until shimmering.

Sear the Steaks: Place the marinated filet mignon on the grill or in the skillet. Sear for about 4-5 minutes on one side, then flip and cook for an additional 4-5 minutes for medium-rare, or until desired doneness.

Rest the Steaks: Once cooked, remove the steaks from the grill or skillet and let them rest on a cutting board for 5-10 minutes. This allows the juices to redistribute.

Serve: Top each filet mignon with a generous dollop of bone marrow butter before serving.