Sweet potato tortilla

Heat a nonstick 20cm frying pan over a medium heat and pour in 50ml oil. Add the onion and ½ tsp salt and cook gently for about 10 minutes, stirring occasionally, until soft. Add the sweet potato slices and continue to fry gently, turning often and pressing down into the oil, for 20-25 minutes until soft and starting to brown.

Tip the onion and sweet potato into a bowl, add the eggs, the remaining ½ tsp salt, some freshly ground black pepper, the smoked paprika and nutmeg. Leave to stand for 5 minutes.

Add the remaining 25ml oil to the pan over a medium heat. Tip in the egg mixture and leave to cook gently for 3-4 minutes until set underneath but runny on top. Put a heatproof plate over the frying pan and, using a tea towel to protect you, quickly flip the pan. Slip the tortilla back into the pan, cooked-side up, and tuck in the edges with a spatula to give it a rounded shape. Cook for another 3 minutes until lightly browned underneath but still a bit runny in the middle. Turn out onto a plate and serve in slices, with a twist of black pepper, aïoli and a green salad, if liked.