Add the rice, onion, turmeric, cardamom and chicken stock to a medium sauté pan or rice cooker. Bring the mixture to a boil over medium heat. Once boiling, cover the pot and reduce the heat to medium-low. Cook until all the water has been absorbed and the rice is tender. Fluff the rice mixture with a fork and season to taste with salt.
For the lamb:
In a large mixing bowl, toss the ground lamb with the shallot, garlic, lemon juice, salt, paprika, cumin, coriander, curry powder, ground cinnamon and black pepper. Be careful not to over mix.
Heat a large sauté pan over medium heat, add the olive oil and heat through. Add the lamb mixture and sauté until golden brown and cooked through. Remove from sauté pan and set aside in a covered bowl until ready to serve.
For the spiced yogurt sauce:
In a medium bowl whisk together the Greek yogurt with the coriander, cumin, white pepper, salt, vinegar, lemon juice and 1 tablespoon of lukewarm water until completely combined. Cover and refrigerate until ready to use.
For serving:
Divide the lettuce among 4 bowls. Top each with a scoop of the rice, lamb, tomato, hot sauce and the spiced yogurt sauce. Serve with a side of pita bread.