Heat the oil in a frying pan and fry the plantain slices for about 2-3 mins on each side until golden brown and cooked through. You might need to do this in two batches. Then cut the fried plantain into smaller pieces.
Pre-heat oven to fan assisted 160C / 180C / 350F / gas 4.
Lightly oil a 6 cup silicon muffin tin (including the top of the tin).
Break the eggs into a bowl and whisk them together, then mix in all the other ingredients.
Add equal amounts of the frittata mixture to each muffin cup.
Bake in the oven for about 20 mins until golden and cooked through.