Combine the garlic, ginger, spices, yoghurt, lemon juice, salt, and pepper in a large bowl.
Spread the marinade over the lamb on a baking tray and refrigerate for 2 to 24 hours.
Scrape off any excess marinade and roast the lamb at 170°C for 3 to 4 hours.
Boil lentils with ginger and turmeric in water for 25-30 minutes until tender, then drain.
Sauté onion, cumin, coriander, and chilli powder in ghee for 2-3 minutes, adding garlic and fresh chilli.
Cook tomatoes until thickened, stir in the lentils, and season with salt and pepper.
Mix flour and salt with water to form a smooth dough and divide into four.
Roll out dough into circles and cook on a hot griddle pan until charred, brushing with ghee.
Shred the lamb meat and serve with the dal, garnished with fresh coriander and flatbreads.