Preheat the oven to 400 F.
In a large bowl, mix your eggs, onion, garlic and seasoning, and fold in the shredded plantains. Allow to sit in fridge while you heat your olive oil.
In round cast-iron pan (or round pie plate, but use a sheet pan underneath when putting in the oven), heat your olive oil in the oven until it bubbles around the back of a wooden spoon.
Once the oil is heated, gently add your plantain mixture to the prepared pan. Spread evenly, and then place into the oven on the upper rack. (Use a sheet pan underneath if using a thinner metal or glass pan)
After the edges begin to brown (about 25-30 minutes) lower the temperature to 300 F and cook until golden and crispy on top, around 10-15 minutes. You can rewarm later in a 200 F oven, if necessary.