Heat the olive oil in a large frying pan over a medium heat. Add the chorizo and cook for around 5 minutes, until crisp. Remove from the pan using a slotted spoon. Set aside.
Add the leeks and cook for 10-15 minutes, until softened. Then add the tomatoes and spinach to the pan and leave to wilt for 1 minute.
Make 4 indents into the spinach mixture and crack a British Lion egg into each one. Cook for around 5-7 minutes, until the eggs are set, covering the pan towards the end to help the eggs cook.
Once cooked, add the chorizo back to the pan, season the eggs and sprinkle over the chilli flakes and spring onions.