Step 1

Place oil into mixing bowl and heat 2 min/120°C/speed 1.

Step 2

Add mustard seeds and heat 30 sec/120°C/speed 1.

Step 3

Add onion, ginger paste and garlic paste and chop 7 sec/speed 5.

Step 4

Scrape down sides of mixing bowl with spatula and cook 8 min/100°C/speed 1.

Step 5

Add all remaining ingredients, except lamb and water, and mix 30 sec/speed 2.

Step 6

Scrape down sides of mixing bowl with spatula, then cook 5 min/100°C/speed 1. Set aside in mixing bowl to cool (approx. 30 minutes).

Step 7

Place lamb in a rectangular roasting dish (approx. 33 x 23 cm) and score several cuts into the lamb. Rub spice mixture over lamb and into cuts. Cover with plastic wrap and place into refrigerator to marinate overnight.

Step 8

Remove lamb, uncover and bring to room temperature (approx. 1 hour).

Step 9

Preheat oven to 150°C. Cover lamb with aluminium foil and roast for 4 hours, carefully adding water (2-3 cm high) into roasting dish halfway through cooking. Serve warm with extra yoghurt.