Southwest Flank Steak with Fresh Tomatillo Salsa

Name: Southwest Flank Steak with Fresh Tomatillo Salsa
Ingredients: 4 medium tomatillos, husked, rinsed, and coarsely chopped (8 ounces); ¼ cup chopped fresh cilantro; 1 medium fresh jalapeño pepper, seeded and finely chopped (see Tip); 1 clove garlic, minced; ¼ teaspoon salt, divided; 1 (1 1/4 to 1 1/2 pound) beef flank steak, 1 inch thick; 1 teaspoon chili powder; ¼ teaspoon ground cumin; ¼ teaspoon garlic powder; ¼ teaspoon ground pepper; ¼ cup crumbled queso fresco or grated Monterey Jack cheese (1 ounce) (Optional)