3 or 4 dried chiles de árbol, stems, seeds removed
1/4 cup fresh cilantro leaves
1 large clove garlic, coarsely chopped
1/4 teaspoon ground black pepper
Flour tortillas (optional)
Fresh cilantro leaves (optional)
Place tomatillos and chiles in medium saucepan; add enough water to cover. Bring to a boil; cook 5 to 8 minutes or until tomatillos are just tender, stirring occasionally. Drain.
Place tomatillo mixture, 1/4 cup cilantro and garlic in food processor or blender container. Cover; process until finely chopped, but not pureed. Season with salt and black pepper, as desired. Set aside.
Meanwhile press 1/4 teaspoon black pepper evenly onto flat iron steaks. Heat large nonstick skillet over medium heat until hot. Place steaks in skillet; cook 13 to 15 minutes for medium rare (145°F) to medium (160°F) doneness, turning occasionally.
Carve steaks across the grain into thin slices; season with salt and black pepper, as desired. Spoon tomatillo sauce over steak. Serve in flour tortillas, if desired. Garnish with additional cilantro, if desired.