How to Make It
Preheat the oven to 350°. In a large Dutch oven, heat 2 tablespoons of the vegetable oil. Add half of the cauliflower, season with a pinch of salt and cook over moderately high heat until it begins to brown, about 5 minutes; transfer to a bowl. Repeat with another 2 tablespoons of oil and the remaining cauliflower.
Heat the remaining 1 tablespoon of oil in the casserole. Add the garlic, ginger and shallots and cook over moderate heat until golden, about 2 minutes. Add the coriander, turmeric and cayenne and cook, stirring, until fragrant. Add the chile and cook until softened. Add the tomatoes, cinnamon stick, lemon zest and water, season with salt and pepper and bring to a boil. Stir in the cauliflower. Cover the casserole and braise in the oven for 35 minutes, or until the cauliflower is tender and the sauce is slightly thickened.
Transfer cauliflower to a serving bowl and spoon the sauce on top. Garnish with the cilantro and cashews and serve.