Grilled Skirt Steak Fajitas Recipe

Name: Grilled Skirt Steak Fajitas Recipe
Ingredients: 1/2 cup soy sauce; 1/2 cup lime juice from 6 to 8 limes; 1/2 cup canola oil; 1/4 cup packed brown sugar; 2 teaspoons ground cumin seed; 2 teaspoons freshly ground black pepper; 1 tablespoon chili powder (see note above); 3 medium cloves garlic, finely minced (about 1 tablespoon); 2 pounds trimmed skirt steak (about 1 whole steak; see note above), cut crosswise into 5- to 6-inch pieces (see here for detailed trimming instructions); 1 large red bell pepper, stemmed, seeded, and cut into 1/2-inch-wide strips; 1 large yellow bell pepper, stemmed, seeded, and cut into 1/2-inch-wide strips; 1 large green bell pepper, stemmed, seeded, and cut into 1/2-inch-wide strips; 1 white or yellow onion, cut into 1/2-inch slices; 12 to 16 fresh flour or corn tortillas, hot; 1 recipe guacamole, for serving, if desired; 1 recipe Pico de Gallo, for serving, if desired; Sour cream, shredded cheese, and salsa, for serving, if desired