1. Remove fillets from refrigerator at least 30 minutes before cooking; pat dry with a paper towel. Sprinkle fillets evenly with 3⁄4 teaspoon salt and 1⁄2 teaspoon pepper.   

2. Preheat oven to 400°.

3. Heat a large cast-iron skillet over medium-high heat for at least 3 minutes; add butter, and heat until melted. Add shallots and garlic. Cook, stirring occasionally, until tender and browned, about 10 minutes. Remove shallots and garlic. Set aside.

4. Add fillets, being careful not to overcrowd skillet. Cook for at least 15 minutes without moving. Sprinkle fillets evenly with remaining 3⁄4 teaspoon salt and remaining 1⁄2 teaspoon pepper. Turn steaks, and brown on the other side for about 15 minutes. Add shallots and garlic to pan.

5. Place skillet in oven. Bake until an instant-read thermometer placed in the center of fillets registers 125° (or to desired degree of doneness), approximately 10 minutes. 

6. Remove fillets from oven. Let rest for 5 minutes. Serve immediately with Herbed Compound Butter, if desired.