Preheat the broiler to high. Grease a baking sheet with olive oil. In a large bowl, combine the cauliflower, 1/3 cup coconut milk, 2 cloves chopped garlic, 1 tablespoon grated ginger, and a pinch of salt. Let sit 10 minutes to "marinate". Spread the cauliflower in an even layer on the prepared baking sheet. Transfer to the oven and broil for 3-4 minutes, until the cauliflower is just beginning to char on the edges. Meanwhile, heat the olive oil in a large skillet over medium heat. Add the onion and cook 5 minutes or until fragrant. Add the remaining garlic and ginger, cooking another 5 minutes. Stir in the garam masala, curry powder, turmeric, and cayenne, and cook until fragrant, about 1 minute.Add the tomato paste and remaining 2 cups coconut milk. Stir to combine, bring the sauce to a boil, cook 5 minutes or until the sauce thickens slightly. Stir in coconut oil. If the sauce seems thick, thin with 1/2 to 1/2 additional coconut milk or water. Add the cauliflower and any juices on the pan and cook, stirring occasionally, until the sauce thickens slightly, about 5 minutes. Remove from the heat and stir in the cilantro. Season with salt and pepper.Serve the cauliflower and sauce over bowls of rice with fresh naan and mango chutney, if desired. Enjoy!