Mix the turmeric, ginger, lemon zest and juice together and toss the chicken into this to coat.
Heat the oil in a large pan and cook the onion and garlic until soft and starting to colour to a golden brown – about five minutes.
Add the curry powder and tomato purée and cook for three minutes, then add the chicken and cover with the chicken stock. Cook for 15-20 minutes until a knife goes easily through the chicken.
To finish, stir through the yogurt and finish with the fresh herbs.