Preparation time: 10 minutes
Cooking time: 1 hour

For the pie:
½ x 85g bag of watercress, chopped
1 onion, finely chopped
1 celery stick, finely chopped
1 carrot, peeled and finely chopped
25g butter
500g minced lamb
1 tbsp Worcestershire sauce
400g can chopped tomatoes
1 tbsp tomato ketchup
1 tsp fresh thyme leaves, roughly chopped

For the mash:
½ x 85g bag watercress, chopped
1kg Desiree potatoes, peeled
25g butter
salt and freshly ground black pepper
50g Cheddar, finely grated

Preheat the oven to 200°C, 400°F, gas mark 6. For the pie, finely chop the onion, celery and carrot. Melt butter in a frying pan and gently fry the vegetable mixture for 8-10 minutes until tender. Remove from the pan and set aside.

Add the lamb to the pan, turn up the heat and brown for about 8-10 minutes. Drain off any excess fat, then add the vegetable mixture, the Worcestershire sauce, tomatoes, ketchup and thyme. Stir and simmer for 20 minutes until reduced then stir in half the watercress.

Meanwhile, for the mash, cut the potatoes into even-sized chunks and cook in boiling, salted water for 20 minutes. Drain and mash with butter and seasoning. Stir in half the Cheddar and the remaining watercress.

Season the meat mixture and spoon into a shallow ovenproof dish. Top with the Cheddar mash. Sprinkle over the remaining cheese and cook for 30 minutes until golden brown and hot.