Meat sliced and fry for about 5 minutes. Then take out and put away. In the same fat put mustard seeds and chopped onion. Fry for about 2-3 minutes. Pre do ginger-garlic paste (Strain with a little water). Add to fried onions. Stir and add dry spices - coriander, cumin, turmeric, cayenne pepper, red pepper and black pepper. Stir for about 10 seconds, and add pre-shredded tomatoes and 100 ml water and sugar. Leave to boil for 5-7 minutes. When sauce thickens add the coconut milk, lemon juice and the remaining 200 ml water. Boil for another 10 minutes and then add the sweet potato, meat and chickpeas. Leave to simmer on the stove until the meat is cooked. Once the meat is cooked get out of the heat and sprinkle the finished dish with garam masala and parsley. Serve with rice or bread.