Shepard's pie with sweet potato

Shepard's pie is one of my favourite dishes that I've been introduced to since moving to England. I love the simplicity of the dish, but also how versatile it can be if you feel adventures. This is a crowed pleaser that spans over generations, the ultimate comfort food!
I like to make mine with some chunky vegetables and sweet potato mash. Scrumptious!

Shepard's pie with sweet potato (serves 6)

• lamb mince
• 1onion
• 2-3 cloves of garlic
• 1carrot
• 1 medium sized courgette
• 2 tomatoes
• app. 6 medium sized potatoes (eg King Edward, not new potatoes)
• 2 orange fleshed sweet potatoes
• a splash of Worcestershire sauce
• a tablespoon of tomato puree
• parsley
• oregano, salt and pepper to taste

I begin by chopping the onion finely and sweating them of on a low heat in a little bit of olive oil (not the extra virgin kind). When the onion is soft, turn up the heat and add the mince. Fry until gently browned. Give it a splash of Worcestershire sauce and a table spoon of tomato puree, finely chop the garlic and add to your pan. At this point I prefer to add a cup of water, put a lid on and simmer gently in the oven for about 1 1/2 hours, but if you are short of time just go ahead to the next step.
Chop the carrot, the tomatoes and the courgette into chunks. Add the vegetables to the mince and season with dried oregano, salt and pepper to taste, and a small pinch of sugar (makes all the flavours come together better, trust me. Cook for a further 20 min.
For the mash, just boil the potatoes and the sweet potatoes for app. 25 min, or until soft enough for mashing. Add a knob of of butter , and if needed a splash of milk. The sweet potato will often make the mash loose enough. Season with salt and pepper.
Assemble the the pie by putting the mince in the bottom of an oven proof dish and top with the mash. For a golden glistening finish, brush with a beaten egg.
Cook in a pre-heated oven 225C for about 30 min, or 20 min if you slow-cooked the mince earlier.
Scatter a hand full of parsley over the finished pie.
Serve with a fresh green salad.
Enjoy!