Cook the green bananas or green plantains until tender. Strain and mash.
In a medium skillet over medium heat place the butter, onion, tomatoes, red bell pepper, garlic and achiote. Cook the mixture for about 7 minutes, and then add to the mashed plantains and set aside.
To serve, place some cayeye on a plate and top with fried egg, shredded cheese and diced avocado.