Heat olive oil in a large cast iron grill pan over medium-high heat. Or preheat outdoor gas grill.
In a small bowl, combine the mustard, Italian seasoning, and garlic powder. Spread mixture over the steak on all sides. Sprinkle with salt and black pepper, to taste.
Place steak on grill and sear on both sides, approximately 2-3 minutes per side.
Reduce heat to medium and cook on one side for 7 minutes. Turn steak and cook for another 5-10 minutes, or until steak reaches desired level of doneness.
Remove from heat, tent with a piece of aluminum foil and let rest for 5-10 minutes before serving.
Notes
The actual cooking time for this recipe will vary depending on the thickness of the meat, the starting internal temperature, and the desired level of doneness.