Carne Asada Tacos

Name: Carne Asada Tacos
Ingredients: ½ cup white vinegar; 2 tablespoons chili powder; 2 tablespoons extra-virgin olive oil; 2 ¾ teaspoons salt, divided; 1 teaspoon garlic powder; 2 pounds flank or skirt steak, trimmed and cut into 3 equal portions; 1 pound tomatoes, chopped; 2-4 fresh jalapeño peppers or serrano chiles, seeded and finely diced; ½ cup chopped onion; ½ cup chopped fresh cilantro; 1 ripe but slightly firm avocado, diced; Juice of 1 lime; 16 5- to 6-inch corn or whole-wheat flour tortillas, warmed; 1/3 cup crumbled Cotija cheese (see Tip) or other shredded cheese