Marcus Wareing's Spanish Tortilla with Alioli

You can use any type of cheese to coat the tortilla.

If you don’t want to layer the chilli and potatoes, you can pour the entire mixture together into the pan on step 4.

1. Heat up a pan on low heat with a generous glug of olive oil. Add the onions first and allow to sweat in the pan. Next, add the thinly sliced potatoes one by one and season generously with salt. Mix well. Add more oil if the potatoes are sticking together. 
2. Create a lid for the saucepan out of greaseproof paper by folding a large piece in half, half again and then form a wedge. Hold the wedge of paper over the pan with the tip of the slice hovering over the centre. Tear off the excess that sits outside of the pan, leaving roughly one inch of excess paper. Open it up to form the circle and cover the pan, pressing the paper until it is touching the onions and potatoes. Cook for 15-20 minutes or until the onions and potatoes are completely soft.
3. Meanwhile, cut the peppers in half, deseed and slice. Cut the chilli in half, deseed and slice. 
4. Scoop half of the potatoes and onion mixture into a deep ovenproof dish. Add most of the pepper and chilli on top, then layer the rest of the potato mixture over. 
5. Crack the eggs into a large bowl. Season generously and whisk together before pouring into the ovenproof dish. 
6. Layer any remaining peppers and chillies on top. Finally, scatter over the cheese and dried herbs.
7. Cook the tortilla in the oven at 180°C for 20-25 minutes until golden brown.
8. For the alioli, slice the garlic gloves and add a good pinch of salt. Then with the back of your knife, crush the garlic to make a paste. 
9. Put the garlic into a blender alongside 2 egg yolks, a spoon of mustard and a drizzle of olive oil. Blitz the mixture, adding more oil a little at a time until the mixture is thick. Allow the oil to roll in gently. 
10. Slice the tortilla into generous portions and serve alongside a dish of alioli.