Place all ingredients for marinade in a glass bowl, mix well and chill for at least 2 hours (ideally over night and remove from fridge 1hour before cooking).
Prepare rice by soaking for at least 30mins and rinsing well in a sieve until the water runs clear.
Add the oil to a large hot pan and fry the cumin seeds until they sizzle, when this happens add the onion and fry until soft and brown.
Pour in the lamb mix, add the tomatoes and continue to cook on a high heat for 5 minutes continually stirring, to make sure the spices are cooked through.
Turn the heat to low, cover and simmer for 25mins to ensure the lamb becomes tender.
Add the bay leaf, rice and vegetable stock, stir and cover again, leave on a low heat for a further 20 minutes.
Turn off the heat, remove lid, add spinach and stir once, replace the lid.
Let this stand for 10mins to ensure the rice is light and fluffy.