Grilled Steak Burritos with Avocado Pico de Gallo

Name: Grilled Steak Burritos with Avocado Pico de Gallo
Ingredients: 1/2 lb. skirt steak; 2 tsp. ground cumin; 2 cloves garlic, minced, divided; Juice of 2 limes (8 tbsp.), divided; 5 tbsp. extra-virgin olive oil; 1 8-oz. can black beans, drained and rinsed; kosher salt; Black pepper; 3 small tomatoes, seeded and finely diced (1 1/2 c.); 1/3 c. minced red onion; 5 tbsp. chopped cilantro, divided; 1 avocado, diced; 1 c. Cooked brown or white rice; 4 8 tortillas; 1 1/2 c. thinly sliced romaine lettuce; Shredded cheddar cheese (optional); Sour cream (optional)