Heat the oil in a wide karahi or deep pan over medium–high heat until it is hot but not smoking.
Add the chicken and cook uncovered, stirring regularly, until it changes colour and begins to lightly brown.
Stir in the garlic paste and ginger paste, letting them cook briefly until fragrant and the raw aroma disappears.
Add the tomatoes and mix well so they coat the chicken evenly.
Cover the pan and allow the tomatoes to soften and break down, stirring occasionally to prevent sticking.
Remove the lid, then add the chilli flakes, black pepper, salt, and bullet chilli, mixing thoroughly.
Continue cooking on medium heat until the tomatoes reduce into a thick masala and the oil visibly separates.
Finish by stirring through the julienned ginger, then cook for a final minute before serving hot.
