Preheat the oven to 400°F then line a baking sheet with a silicone mat or parchment paper. Add the eggplant to a large bowl then drizzle with coconut oil and toss until evenly coated. Spread out on the baking sheet and roast in the oven until softened and light golden brown, about 30 minutes, stirring half way through.Meanwhile prepare the raita by combining all of the ingredients in a medium size bowl. Cover and place in the refrigerator while you prepare the curry.Warm a large skillet over medium heat then add the mustard seeds, cumin, coriander, curry and cayenne. Toast for about 2 minutes, until fragrant. Pour in 1/2 cup water (carefully, if the pan is too hot the water will boil and splatter) then add the onion, garlic and ginger along with 1/4 teaspoon salt. Cook until softened, about 5 minutes.Pour the cans of tomatoes with their juices in the skillet. Once the eggplant is done roasting add it along with the chickpeas to the skillet. Stir to combine and cook until heated through. Serve warm with basmati rice and cucumber lime raita, and enjoy!