Puree tomatoes, chopped onion and chiles in a blender, scraping down the sides as needed, to make a smooth sauce.
Heat 2 tablespoons oil in a large skillet over medium-high heat.
Add raisins and cashews, saute and stir until raisins are plump and the nuts are lightly browned (1-3 minutes). Transfer to a plate with a slotted spoon.
Add cumin seeds, cardamom pods, bay leaves and cinnamon sticks to the pan, saute and stir until fragrant (30 seconds- 1 minute).
Add the sliced onion and cook, stirring, until lightly brown (2-3 minutes).
Carefully pour in the pureed tomato mixture and reduce heat to medium. Stir in garam masala, 3/4 teaspoon of salt and turmeric.
Simmer, partially covered, stirring occasionally, until most of the liquid evaporates (about 15 minutes).
Meanwhile, Place rice in a medium bowl. Then cover with cold water and let sit for 20 minutes. Drain.
Stir mustard greens, cauliflower, chickpeas and 1 cup of water into the tomato sauce. Cover and remove from the heat.
Lightly coat a 9x13 inch baking dish with cooking spray, set aside.
Heat the remaining 1 tablespoon oil in a medium saucepan over medium-high heat. Add the drained rice and saffron, and carefully stir to coat the rice with the saffron.
Add the remaining 1 cup water and 1/4 teaspoon salt. Stir once to incorporate ingredients. Bring to a boil over medium-high heat. Cook, uncovered, until the water has evaporated from the surface and craters are starting to appear in the rice (5-8 minutes). Remove from heat.
Spread half the chickpea curry mixture evenly in the prepared baking dish. Spread the rice mixture on top of the curry. Spoon the remaining chickpea mixture over the rice. Scatter the reserved raisins and cashews over the top.
Cover with foil and bake until the rice is tender (45-55 minutes).
Remove the bay leaves, cardamom pods and cinnamon sticks before serving.