Heat the oil in a frying pan on a medium heat (I used an 8 inch pan for this).

Add the kale and cook for 5 minutes until wilted and soft.

In a bowl, beat the eggs and add the sage, parmesan, salt and pepper.

Pour the egg mixture into the frying pan and cook for 7-10 minutes until firm.

Heat the grill on a medium heat and place the frittata underneath it, until the top is golden and firm.

Eat and enjoy!