Peel and slice the plantains lengthwise without cutting all the way through. Fry in oil until golden and tender, then drain on paper towels. While hot, use a spoon to widen the slice and shape the plantains into boats. Set aside.
In a pan over medium heat, combine ground beef, bell peppers, onion, garlic, adobo, sazón, salt, and pepper. Cook until the vegetables soften and the meat browns, about 5 minutes. Stir in tomato sauce and vinegar, cooking for 10 minutes until most liquid absorbs. Optionally add capers and raisins, then let cool.
Preheat oven to 350°F. Place plantain boats on a baking sheet, fill with cheese, picadillo, and another layer of cheese. Bake for 10-15 minutes until the cheese melts, then garnish with cilantro, lime wedges, and avocado. Serve warm. Buen provecho!