Sumac and cumin spiced lamb

This is the kind of simple, meat and potatoes dish that I tend to revisit whenever I need a fuss free yet fulfilling supper. It can easily be altered according to what vegetables you may have hanging around in your fridge and needs little attention in terms of cooking.
Aside from the sumac, which can be purchased from most supermarkets or middle Eastern stores, the recipe uses standard spices. The fresh coriander can be substituted with parsley if coriander isn't to your taste.

Ingredients to feed 2:
300g lamb or mutton mince
350g new potatoes, large pieces cut into quarters
1 medium onion, finely chopped
1 large clove of garlic, finely chopped
a large handful of leafy greens such as spinach, swiss chard or kale
1 carrot, shaved with a peeler or very finely chopped
A small bunch of fresh coriander, leaves picked and stalks finely chopped
1 teaspoon of cumin
1 teaspoon of sumac plus extra for sprinkling
1/2 teaspoon of turmeric
1/4 teaspoon chilli flakes
sea salt & black pepper
Creme fraiche to serve

Cover the potatoes with enough water to top them by an inch. Bring it to boil and cook for 20 mins until tender. Drain and set aside.
Chop the vegetables whilst the potatoes are cooking.
Put a frying pan on a medium heat and brown the lamb mince with the onions (5 mins approximately). There is no need for oil as the lamb has plenty of fat in it.
To remove some of the fat, take the frying pan off the heat once the meat is cooked, tilt the pan and push the meat to the top of it. The fat will drain to the bottom and you can spoon it off. This part is optional, although I do tend to remove around 1-2 tablespoons of the fat.
Put the frying pan back on the medium heat, add the garlic, cumin, coriander stalks, sumac, chilli, turmeric and season well with salt and pepper. Cook for 2-3 minutes.
Add your vegetables and cook for another couple of minutes.
Add the potatoes, stir well and cook for another minute or two. Check the seasoning and season to your taste.
Divide the lamb & potatoes between two plates, sprinkle some sumac and fresh coriander leaves and put a dollop of creme fraiche on top.