Preheat the oven to 400ºF.
Place onion, garlic and ginger in a food processor along with the cilantro and pepper. Whiz into a fine paste. Set aside.
In a large skillet, add the spices on a low heat and dry-fry for 1 minute, or until is smelling fantastic, stirring constantly. Add in the paste and cook for another 5-8 minutes over medium heat, or until softened, stirring regularly. Stir in the peanut butter, mango chutney, tamarind paste, and season with sea salt. Add a small amount of water so the paste isn't too thick. Turn off heat and set aside.
Leaving them intact at the stalk, cut the eggplants into quarters lengthwise (if using small Indian eggplants) or slice them like you would Hasselback potatoes along the width from end to end, with about 1/4 inch of space between each slice (for the longer Asian eggplants). Only slice down about 3/4 into the eggplants. Arrange the sliced eggplants in a casserole dish. Top with the spiced paste (spread evenly) and the cherry/grape tomatoes. Bake UNCOVERED for 15-20 minutes, until the tomatoes have roasted down. Reduce temperature to 375 degrees. Remove the casserole from the oven and pour the can of lite coconut milk over the top of the casserole. Sprinkle with a few more pinches of salt. Cover with foil and bake for 40 minutes, or until thickened and reduced, removing the foil halfway.