Combine lentils in a saucepan with enough cold water to cover generously, bring to the boil over high heat, cook until just tender (10-15 minutes), strain and cool under running water. Transfer to a bowl and set aside.
Meanwhile, for Tandoori-style lamb, dry-roast spices in a small saucepan over medium-high heat until fragrant (30 seconds). Process in a food processor with yoghurt, onion, lemon juice, garlic and ginger, until smooth, season to taste. Combine in a bowl with lamb, turn to coat, set aside for 10 minutes. Heat vegetable oil in a large frying pan over medium-high heat, add lamb, turn occasionally until cooked to your liking (8-10 minutes for medium-rare). Set aside to rest for 5 minutes.
Meanwhile, heat olive oil in a small saucepan, add mustard seeds and ginger and cook until seeds pop (30 seconds-1 minute). Remove from heat, add extra-virgin olive oil and lemon juice, season to taste, pour over lentils. Add remaining ingredients, toss to combine and serve with lamb and yoghurt.
This recipe is from the January 2011 issue of Australian Gourmet Traveller.