Peel plantains and cut in half. Add plantains to a pot of water over high heat until soft.
Remove from heat. Place plantains in a bowl with butter and mash until completely smooth. Set aside.
Add onions, garlic, and peppers to a pan over low to medium heat. Cook until soft.
Add beef and seasonings to the pan and cook.
When almost fully cooked, mix in tomato paste. Set aside.
Butter a baking dish and add ½ of the plantain mixture. Use a fork to flatten.
Add beef mixture to the dish and flatten.
Add the rest of the plantain and top with mozzarella cheese.
Bake for 20 minutes at 375°.
Let cool and serve. Enjoy!