Crispy Shredded Cuban Beef With Pan Fried Onions and Plantains Recipe

Name: Crispy, Shredded Cuban Beef With Pan-Fried Onions and Plantains Recipe
Ingredients: For the Beef and Onions:; 2 medium onions, peeled, divided; 2 1/2 pounds flank steak; 2 carrots, peeled and cut into chunks; 2 celery stalks, cut into chunks; 6 cloves garlic, divided; 2 bay leaves; One quarter cup fresh-squeezed lime juice; One quarter cup fresh-squeezed lemon juice; 2 teaspoons dry sherry; 1 teaspoon cumin; Kosher salt; Cracked black pepper; One-half cup, plus 1 tablespoon olive oil, divided; 3 cups cooked white rice; 2 limes, cut into wedges; For the Plantains:; 3 ripe plantains; 1/4 cup brown sugar