Cook the rice in boiling, lightly salted water for 10-12 minutes, until al dente. Drain well and tip into a large bowl.
Add the lentils and coriander. Gently mix together and season to taste.
Meanwhile, heat a large, deep frying pan over a high heat. When hot, add minced beef and cook for 5 minutes, stirring, until browned. Stir in the curry sauce, then quarter-fill the jar with water and rinse out into the pan. Simmer for 3-4 minutes – you want to keep the mince fairly juicy.
Add the rice mixture and gently mix everything together. Divide between plates and serve with mango chutney and poppadoms, if you like.