Begin by heating white vinegar and sugar in a large saucepan over medium heat until the sugar dissolves completely.
Into the same saucepan, add chopped mangoes, chopped onion, minced garlic, and grated ginger. Mix everything well.
In a separate small pan, dry roast cumin seeds and mustard seeds until they start to pop. Grind them into a coarse powder using a mortar and pestle or a spice grinder.
Add the ground cumin and mustard seeds, along with ground coriander, ground turmeric, chili flakes, salt, ground cinnamon, and ground cloves to the mango mixture. Stir thoroughly to combine all the flavours.
Let the mixture gently simmer for about 30-40 minutes, stirring occasionally, until the chutney thickens, and the mangoes become soft and translucent.
Taste the chutney and adjust the sweetness and spiciness to your liking by adding more sugar or chili flakes if desired.
Once the chutney reaches your desired consistency and flavour, remove the saucepan from the heat and let it cool.
Transfer the cooled mango chutney into clean, airtight jars, and store them in the refrigerator.