Heat 15ml of oil in a frying pan and sauté onion, garlic, ginger, and both chillies.
Add corn kernels and chopped tomatoes and cook for 10 minutes.
Dissolve sugar in vinegar and tomato juice in a separate pan, then combine with the tomato mixture.
Dry fry mustard seeds, cumin, ras-el-hanout, and paprika, grind them, and add to the chutney.
Fry curry leaves in 15ml of oil until crackling, drain, and stir into the mixture.
Pulse half of the mixture in a blender with water and fold it back into the chunky portion.
Heat for 2 minutes, season to taste, and stir in coriander before transferring to jars.
Seal jars tightly and submerge in boiling water for 30 minutes.
Cool completely and verify the seal before storing.