Plantains Stuffed with Picadillo

Name: Plantains Stuffed with Picadillo
Ingredients: Nonstick cooking spray, for the baking sheet and plantains; 6 large ripe plantains; 3 cups vegetable oil; 2 medium onions, chopped; 1 red bell pepper, seeded and chopped; 2 cloves garlic, minced; 1 tablespoon tomato paste; 1 1/2 pounds ground beef; 1/2 cup Manzanilla olives, sliced; 1 poblano chile, chopped; Kosher salt; 1 1/2 cups canned tomatoes, diced and juices reserved; 1 1/2 teaspoons ground cumin; 1 1/2 teaspoons paprika; 1/2 teaspoon garlic powder; 1 cup Cotija, crumbled; Fresh cilantro leaves, for garnish