Pan-fried tuna with citrussy quinoa salad

Method

1. Heat a glug of oil in a large, deep frying pan over a medium heat, then gently fry the leeks and carrots for 5 minutes. Add the quinoa and stir together. Cook for 1 minute, then pour in the stock. Reduce the heat to low-medium and simmer gently for 20 minutes until the quinoa is just cooked. 
2. Stir in half the parsley and half the orange zest and juice, then taste and season with salt and pepper. Cook for 1 minute more, then turn off the heat.
3. Heat a griddle pan until smoking hot. Season the tuna steaks with salt and pepper, then put in the hot pan and cook for 1½ minutes on each side for medium rare. Slice, then divide the steaks, cooked quinoa and watercress among 4 plates. Squeeze over the remaining orange juice and sprinkle with the orange zest to serve.