Heat the olive oil in a large frypan over medium-high heat. Cook and stir the onions in the hot oil until translucent, about 5 minutes. Add the ginger-garlic paste and continue cooking another 5 minutes.
Reduce heat to medium; stir the tomatoes into the mixture and cook until the tomatoes are pulpy, 5 to 10 minutes. Season with the cayenne pepper, curry powder, garam masala, turmeric and cumin; cook and stir another 5 minutes.
Add the chicken and potatoes to the mixture in the frypan; simmer, stirring occasionally, until the potatoes are tender and the chicken is no longer pink in the center, about 20 minutes. Sprinkle the coriander over the mixture and continue simmering another 10 minutes. Serve hot.