To make the salad, mix the tomatoes and red onion together in a large bowl. Drizzle over the olive oil and vinegar. Season to taste with salt and pepper, and top with some of the fresh coriander. Set aside until needed.
Meanwhile, warm the curry in a saucepan over a high heat. Bring to the boil, then reduce the heat to a simmer for 6 minutes until piping hot. If the curry is too thick, a splash of water will loosen it a little.
Place all the flatbread ingredients in a large bowl and mix together to form a dough. On a lightly floured surface, knead the dough for 1 minute until smooth, adding a little extra flour if it is too wet. Divide the dough into 4 equal pieces and flatten each one with a rolling pin or your hand to a thickness of about 2cm (1 in).
Heat a non-stick frying pan over a high heat until hot, then add the flatbreads in batches. Cook for 30 seconds on each side until lightly browned.
Serve the curry alongside the hot flatbreads and red onion salad, with a wedge of lime on the side. Sprinkle with the remaining fresh coriander before serving.