In a large pot, combine chicken with oil and yoghurt over medium heat. Stir together and add the cumin, red capsicum, ginger, garlic paste, salt and green capsicum. Stir all together; cover pot and simmer over low heat until the oil separates.
Meanwhile, dice the potatoes into large chunks. When the chicken looks cooked and is no longer pink inside (after 20 to 30 minutes), add the potatoes and cook on low heat until tender, adding a little water if necessary. When chicken and potatoes are done, turn off heat. Garnish with chopped coriander and serve. Enjoy!