Step 1Combine the oil, lime juice, tomatoes, chiles, ginger, garlic, coconut sugar and salt in a large saucepan. Set over medium-high heat and bring to a boil, stirring occasionally. Continue boiling, stirring occasionally, until the mixture is jammy and reduced by half, about 25 minutes. Be careful as the mixture will splatter while it cooks.
Step 2Transfer the mixture to a blender and add the coconut and chaat masala. Blend until almost smooth. Transfer to a serving bowl and season to taste with salt.