Boil the potatoes for 10 minutes until just tender, then drain.
Heat the oil in a medium frying pan and fry the bacon for 5 minutes until tender. Add the leek and fry for 3 minutes until soft. Add the drained potatoes and fry for a further 1-2 minutes.
Beat the eggs with the seasoning and stir in the cheese, then pour this over the potatoes in the pan. Cook for 3-4 minutes, without stirring, then cover with a lid, turn the heat down low and cook gently for 5-8 minutes until the egg has set.
Slide onto a plate and leave to cool for 5 minutes before cutting into wedges. Serve hot or cold with a side salad.
To make individual frittatas, divide the potato, leek and bacon mixture between 6 greased, deep muffin tins (10x4cm/4x1 1in) and pour the egg and cheese mixture over each. Bake at Gas 4, 180°C, fan 160°C for 25 minutes. Allow to cool before turning out.
See more bacon recipes
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home.