Shepherd's Pie with Leftover Rack of Lamb

We had leftover lamb from Christmas. Of course, I googled recipes for leftover rack of lamb. What else would I do? A recipe popped up from Mrs. Jones's Kitchen. It was a perfect dinner. I love it when we have all the ingredients in the house. 

Ingredients-
500g (18 oz) leftover roast lamb, finely chopped

1 tablespoon olive oil

1 large onion, finely diced

1 celery stick, finely diced

2 carrots, finely diced

2 cloves garlic crushed

1 tablespoon fresh rosemary, finely chopped

1 tablespoon tomato purée

500ml (2 c) chicken stock

dash Worcestershire sauce 

salt

black pepper

Mashed Potatoes:

800g (1.75 lb) russet potatoes, peeled and chopped into cubes

1 tablespoon butter

60ml (1/4 c) milk

pinch salt

Method-

Preheat the oven to 400˚F 

In a medium saucepan over a low heat, add the olive oil and diced onion, carrots and celery, and cook until soft – this takes around 10 minutes.

Add the crushed garlic and finely chopped rosemary and cook for 1 minute before adding the tomato purée. 

Cook for 1 minute.

Add the chopped cooked lamb, stock, Worcestershire sauce, and season with salt and pepper. 

Turn the heat up and bring to a boil, then turn the heat down slightly and simmer for 15 minutes.

Cook the Potatoes:

Boil the potatoes in salted water for 15-20 minutes, until tender.

Drain well, then add the butter, milk, and salt, and mash with a potato masher until smooth.

Place the lamb into the bottom of a 20 x 27 cm (7.8 x 10.5") or similar-sized, baking dish.

Spoon the mashed potatoes over the surface and smooth them out with the back of a spoon.

With a fork, drag lines across the top of the mashed potatoes – these will become crispy in the oven.

Place in the preheated oven and bake for 20-25 minutes until golden.

Eat straight away.