Chorizo and Feta Frittata

• 250g potatoes, peeled and sliced into 1cm cubes
• 5 tbsp olive oil
• 1 onion, peeled and sliced
• 6 free-range eggs
• 75ml single cream
• 1 tsp sea salt
• 1 tbsp fresh marjoram, chopped (dried is fine if you can't get it)
• 125g chorizo, sliced
• 125g feta cheese, crumbled

1. Preheat the oven to 180C/350F/Gas 4.
2. Place the potatoes into a saucepan of boiling water. Boil for five minutes, or until just cooked. Do not overcook the potatoes or they will go mushy. Drain the potatoes of the excess water and set aside.
3. Heat a 25cm/10in ovenproof frying pan. Add three tablespoons of olive oil and the sliced onion to the pan. Cover the frying pan with a saucepan lid and sweat the ingredients over a gentle heat until the onion becomes soft and slightly golden. Then remove from the heat and set aside.
4. Whisk the eggs in a clean bowl until they are slightly frothy. Then add the cream, the salt and the fresh marjoram.
5. Add the sliced chorizo, the cooked onions and the potatoes to the bowl and mix well.
6. Heat the remaining olive oil in the frying pan. When the oil is hot, pour in the egg mixture and stir briefly to distribute the ingredients evenly.
7. Sprinkle the crumbled feta cheese on to the top of the mixture. Place the pan in the preheated oven and bake for 25-35 minutes or until the centre of the mixture has set. Then remove from the frittata from the oven and allow it to cool for a couple of minutes.
8. To serve, place the frittata onto a large serving plate or a large cake tin lined with baking parchment (if you want to transport it on a picnic). Serve warm or at room temperature.